This unit view groups 17 original DASKEREL lesson packs for an Oak topic sequence. The older export has 17 source lesson records; 17 have exact matching original packs here. Live source pages may contain additional lessons. This count is not an academic approval or a claim that the full subject course is complete.
Describe a rule that works for every pattern number
Test a rule with a new case
Vocabulary: term · position · generalise · constant
Retrieve previous learning
What is the difference between adding 3 each time and multiplying a number by 3?
Check: Adding 3 gives a fixed increase; multiplying by 3 scales the chosen number.
Learn the concept
Suppose a pattern has 4, 7, 10, 13 tiles. The increase of 3 tells us how consecutive terms relate, but the rule for any position also needs a starting adjustment. At position 1, three lots of the position gives 3, so add 1. In words: triple the position, then add one.
A rule must work beyond the first few cases. Position 10 gives 3 × 10 + 1 = 31. Checking positions 1 and 2 gives 4 and 7; this supports the rule, while a visual explanation of three tiles added at each step explains why it continues.
Worked model
List position → tiles: 1 → 4, 2 → 7, 3 → 10.
The change of 3 suggests three times position.
At position 1, 3 needs one more tile, giving triple position plus 1.
Test position 4: 3 × 4 + 1 = 13.
Guided practice
A pattern has 6, 10, 14 tiles at positions 1, 2, 3. Give a word rule.
Hint: Use the change of 4, then adjust the value at position 1.
Check the guided answer
Multiply the position by 4 and add 2. Position 3 gives 4 × 3 + 2 = 14.
Independent practice
Write your own response to every question before viewing the model answers. Your writing stays in this page session; this activity does not submit, store or grade it. Avoid including private information.
Find and correct a misconception
“A common difference is the complete rule for any position.”
Correction: It describes the step; a direct rule also needs the position and an adjustment.
Extend and reflect
Can two rules agree for the first three terms but differ later?
Guidance: Yes. Finite examples alone do not prove a unique rule; explain the construction of the pattern.
Take the end-of-unit checkWhere this lesson could lead · Mathematics GCSE → Daskerel Mathematical Sciences
This lesson practises: Describe a rule that works for every pattern number. Quantitative reasoning supports later mathematical, data and engineering study.
Next school subject:Mathematics GCSE. Check the subject and examination board that fit your school.
Later credential exploration: No subject-specific professional credential is mapped from this lesson. Explore the credential catalogue after choosing a later specialism.
This is an exploratory route, not a promise of admission, a qualification, certification eligibility or employment. Years 7–9 learning is an early foundation; any later credential may require substantial study, experience or local approval.
An equation says two expressions have the same value. Draw one bar for x + 5 and an equal bar of length 17. Removing a length of 5 from each side leaves x equal to 12. This is the inverse of adding 5.
A different equation, 3x + 2 = 20, has three equal x segments and a 2 segment. Remove 2 from both equal bars, leaving 3x = 18; divide both bars into three equal parts, so x = 6. Substitute back: 3 × 6 + 2 = 20.
Worked model
Draw x + 5 and 17 as equal bars.
Remove 5 from both sides: x = 17 − 5.
Calculate x = 12 and check 12 + 5 = 17.
Guided practice
Solve 2x + 3 = 15 using equal bars.
Hint: Remove the 3 segment, then split the remaining bar in two.
Check the guided answer
2x = 12, so x = 6. Check 2 × 6 + 3 = 15.
Independent practice
Write your own response to every question before viewing the model answers. Your writing stays in this page session; this activity does not submit, store or grade it. Avoid including private information.
Find and correct a misconception
“Moving a term across the equals sign automatically changes its sign.”
Correction: State the operation performed on both sides; this preserves equality and explains the sign change.
Extend and reflect
Solve 3(x + 2) = 21 with a bar model.
Guidance: Three equal groups each measure 7, so x + 2 = 7 and x = 5.
Take the end-of-unit checkWhere this lesson could lead · Mathematics GCSE → Daskerel Mathematical Sciences
This lesson practises: Represent an unknown as an equal-length bar. Quantitative reasoning supports later mathematical, data and engineering study.
Next school subject:Mathematics GCSE. Check the subject and examination board that fit your school.
Later credential exploration: No subject-specific professional credential is mapped from this lesson. Explore the credential catalogue after choosing a later specialism.
This is an exploratory route, not a promise of admission, a qualification, certification eligibility or employment. Years 7–9 learning is an early foundation; any later credential may require substantial study, experience or local approval.
Vocabulary: variable · generalised number · expression · substitute
Retrieve previous learning
What operation turns a number into three more than itself?
Check: Add 3 to the number.
Learn the concept
The phrase 'three more than a number' can be written n + 3. The letter n does not secretly mean one fixed chosen number; in a general expression it can take many values. For n = 4 the expression is 7, and for n = 10 it is 13.
A rule such as twice a number plus one is 2n + 1. Order matters: 2(n + 1) means double the sum, which is 2n + 2. Substitute n = 3 to see 7 versus 8, a counterexample to treating them as the same.
Worked model
Choose n for the input number.
Translate 'five less than double the number' to 2n − 5.
At n = 6, calculate 12 − 5 = 7; the expression remains general.
Guided practice
Write 'four times a number, then subtract two' using p and evaluate at p = 5.
Hint: The multiplication happens before the subtraction.
Check the guided answer
4p − 2; at p = 5 the value is 4 × 5 − 2 = 18.
Independent practice
Write your own response to every question before viewing the model answers. Your writing stays in this page session; this activity does not submit, store or grade it. Avoid including private information.
Find and correct a misconception
“A letter always stands for one unknown answer.”
Correction: A letter can represent any permitted input in a general rule; an equation may instead constrain it to particular values.
Extend and reflect
Invent two expressions equal at n = 2 but unequal at n = 3.
Guidance: For example n + 2 and 2n are both 4 at n = 2, but are 5 and 6 at n = 3.
Take the end-of-unit checkWhere this lesson could lead · Mathematics GCSE → Daskerel Mathematical Sciences
This lesson practises: Write a general rule using a letter. Quantitative reasoning supports later mathematical, data and engineering study.
Next school subject:Mathematics GCSE. Check the subject and examination board that fit your school.
Later credential exploration: No subject-specific professional credential is mapped from this lesson. Explore the credential catalogue after choosing a later specialism.
This is an exploratory route, not a promise of admission, a qualification, certification eligibility or employment. Years 7–9 learning is an early foundation; any later credential may require substantial study, experience or local approval.
Vocabulary: coefficient · power · quotient · brackets
Retrieve previous learning
What is 4 × 4 × 4?
Check: 64.
Learn the concept
Algebra removes unnecessary multiplication signs: 3a means 3 × a, while ab means a × b. The notation a² means a × a, not 2a. If a = 4, then a² = 16 and 2a = 8.
The expression a/b means a divided by b, with b nonzero. Brackets show a grouped operation: 2(a + b) doubles both terms, while 2a + b doubles only a. Write 1a simply as a, and 0a as 0.
Worked model
Translate 'three times x plus its square' to 3x + x².
At x = 2, calculate 3 × 2 + 2² = 6 + 4.
The value is 10, not (3 × 2 + 2)².
Guided practice
Write 5 × y × y without multiplication signs and evaluate at y = 3.
Hint: The two y factors make a square.
Check the guided answer
5y²; at y = 3 this is 5 × 9 = 45.
Independent practice
Write your own response to every question before viewing the model answers. Your writing stays in this page session; this activity does not submit, store or grade it. Avoid including private information.
Find and correct a misconception
“A square on a letter means multiply the letter by two.”
Correction: A square is multiplication by itself: a² = a × a.
Extend and reflect
Why is a/b undefined when b = 0?
Guidance: No number times zero can recover a nonzero numerator; division by zero is not defined.
Take the end-of-unit checkWhere this lesson could lead · Mathematics GCSE → Daskerel Mathematical Sciences
This lesson practises: Read 3a, a² and a/b correctly. Quantitative reasoning supports later mathematical, data and engineering study.
Next school subject:Mathematics GCSE. Check the subject and examination board that fit your school.
Later credential exploration: No subject-specific professional credential is mapped from this lesson. Explore the credential catalogue after choosing a later specialism.
This is an exploratory route, not a promise of admission, a qualification, certification eligibility or employment. Years 7–9 learning is an early foundation; any later credential may require substantial study, experience or local approval.
In 5x² − 3x + 8, the terms are 5x², −3x and 8. The coefficient of x² is 5, and the coefficient of x is −3. In 5x² the factors include 5, x and x. A factor multiplies; a term is separated by addition or subtraction at the top level.
An expression such as 2x + 5 has no equals sign. An equation such as 2x + 5 = 11 asks which x makes it true. An identity such as 2(x + 3) = 2x + 6 is true for every x because of the distributive law. An equation can sometimes have more than one solution, so do not define an equation as having exactly one.
Worked model
Write 4y − 7 as terms 4y and −7.
Identify the coefficient of y as 4.
Identify 4 and y as factors of 4y.
2(4 + 3) = 2 × 4 + 2 × 3 illustrates an identity.
Guided practice
In 6a² + 2a − 9, give the coefficient of a², coefficient of a and constant.
Hint: Keep the sign with its term.
Check the guided answer
They are 6, 2 and −9 respectively.
Independent practice
Write your own response to every question before viewing the model answers. Your writing stays in this page session; this activity does not submit, store or grade it. Avoid including private information.
Find and correct a misconception
“Every statement with an equals sign is an identity.”
Correction: An identity holds for all permitted values; an equation may hold only for certain values.
Extend and reflect
Explain why x + x = 2x is an identity.
Guidance: Both sides have the same value for every x, since adding two copies of x is doubling x.
Take the end-of-unit checkWhere this lesson could lead · Mathematics GCSE → Daskerel Mathematical Sciences
This lesson practises: Identify terms, coefficients and factors. Quantitative reasoning supports later mathematical, data and engineering study.
Next school subject:Mathematics GCSE. Check the subject and examination board that fit your school.
Later credential exploration: No subject-specific professional credential is mapped from this lesson. Explore the credential catalogue after choosing a later specialism.
This is an exploratory route, not a promise of admission, a qualification, certification eligibility or employment. Years 7–9 learning is an early foundation; any later credential may require substantial study, experience or local approval.
Year 7 · Algebra · original lesson pack
DASKEREL beta · internal AI review pending
Distinguish a specific unknown from a variable input
In x + 7 = 15, x is an unknown constrained by the equation: x must be 8. In y = 2x + 1, x may vary and y changes with it. A table for x = 0, 1, 2 gives y = 1, 3, 5; this rule describes many input-output pairs.
The same symbol can play different roles in different contexts. State what the domain permits: in a ticket-counting model, x might be a whole number at least zero; in an abstract linear graph, negative or fractional x may be permitted.
Worked model
For x + 7 = 15, subtract 7 from both sides to get x = 8.
For y = 2x + 1, choose x = 8 to obtain y = 17.
Changing x to 9 changes y to 19, so x varies in the rule.
Guided practice
Is t a specific unknown or a variable in t/2 = 6 and in p = t/2?
Hint: Ask whether one value is required or many inputs are allowed.
Check the guided answer
In t/2 = 6 it is constrained to t = 12. In p = t/2 it can vary with p, subject to the context.
Independent practice
Write your own response to every question before viewing the model answers. Your writing stays in this page session; this activity does not submit, store or grade it. Avoid including private information.
Find and correct a misconception
“A variable has no restrictions because it can change.”
Correction: A variable can vary only within the values allowed by its definition or context.
Extend and reflect
Can an equation have a variable on both sides and still specify one unknown?
Guidance: Yes: 2x + 3 = x + 8 has x = 5, found by preserving equality.
Take the end-of-unit checkWhere this lesson could lead · Mathematics GCSE → Daskerel Mathematical Sciences
This lesson practises: Interpret a letter in an equation. Quantitative reasoning supports later mathematical, data and engineering study.
Next school subject:Mathematics GCSE. Check the subject and examination board that fit your school.
Later credential exploration: No subject-specific professional credential is mapped from this lesson. Explore the credential catalogue after choosing a later specialism.
This is an exploratory route, not a promise of admission, a qualification, certification eligibility or employment. Years 7–9 learning is an early foundation; any later credential may require substantial study, experience or local approval.
Three consecutive whole numbers can be written n, n + 1 and n + 2. Their sum is 3n + 3 = 3(n + 1), so it is three times the middle number for every whole number n. The algebra explains the pattern, rather than checking only a few examples.
A counterexample disproves a universal claim. 'The square of every number is greater than the number' fails at 0, since 0² = 0, and at 1. Some statements need a stated domain; 'the sum of two odd whole numbers is even' works because (2a + 1) + (2b + 1) = 2(a + b + 1).
Worked model
Represent consecutive numbers as n, n + 1, n + 2.
Add to obtain 3n + 3.
Factor to 3(n + 1), which is three times the middle number.
Guided practice
Show that two consecutive whole numbers always sum to an odd number.
Hint: Write the numbers as n and n + 1.
Check the guided answer
Their sum is 2n + 1, one more than an even number, so it is odd.
Independent practice
Write your own response to every question before viewing the model answers. Your writing stays in this page session; this activity does not submit, store or grade it. Avoid including private information.
Find and correct a misconception
“Several confirming examples prove a statement for every number.”
Correction: Examples can suggest a rule; an algebraic argument proves it for the stated domain, while one counterexample disproves it.
Extend and reflect
Does the consecutive-square result hold for negative integers?
Guidance: Yes. The expression 2n + 1 is odd for any integer n; check the meaning of consecutive squares in context.
Take the end-of-unit checkWhere this lesson could lead · Mathematics GCSE → Daskerel Mathematical Sciences
This lesson practises: Write a statement that holds for all permitted inputs. Quantitative reasoning supports later mathematical, data and engineering study.
Next school subject:Mathematics GCSE. Check the subject and examination board that fit your school.
Later credential exploration: No subject-specific professional credential is mapped from this lesson. Explore the credential catalogue after choosing a later specialism.
This is an exploratory route, not a promise of admission, a qualification, certification eligibility or employment. Years 7–9 learning is an early foundation; any later credential may require substantial study, experience or local approval.
Vocabulary: substitution · evaluate · order of operations · negative
Retrieve previous learning
What is (−3)²?
Check: 9, because (−3) × (−3) = 9.
Learn the concept
To evaluate 2x² − 3x at x = −2, write 2(−2)² − 3(−2). Square the entire negative number first: 2 × 4 + 6 = 14. Substitution with brackets avoids confusing −2², which by convention is −(2²).
A table can show how an expression changes. For y = x² + 1, inputs x = −2, 0, 2 give y = 5, 1, 5. The equal outputs at opposite inputs come from squaring; they do not imply all inputs produce the same result.
Worked model
Write 2x² − 3x with x = −2 as 2(−2)² − 3(−2).
Calculate the power first: (−2)² = 4.
Then 8 − (−6) = 14.
Guided practice
Evaluate a² + 2a for a = −3.
Hint: Use brackets for both copies of the negative input.
Check the guided answer
(−3)² + 2(−3) = 9 − 6 = 3.
Independent practice
Write your own response to every question before viewing the model answers. Your writing stays in this page session; this activity does not submit, store or grade it. Avoid including private information.
Find and correct a misconception
“When x = −2, x² is −4.”
Correction: The square of the substituted number is (−2)² = 4; keep brackets around negative inputs.
Extend and reflect
Find all real x for which x² + 1 = 10.
Guidance: x² = 9, so x = 3 or x = −3.
Take the end-of-unit checkWhere this lesson could lead · Mathematics GCSE → Daskerel Mathematical Sciences
This lesson practises: Evaluate an expression for a specified value. Quantitative reasoning supports later mathematical, data and engineering study.
Next school subject:Mathematics GCSE. Check the subject and examination board that fit your school.
Later credential exploration: No subject-specific professional credential is mapped from this lesson. Explore the credential catalogue after choosing a later specialism.
This is an exploratory route, not a promise of admission, a qualification, certification eligibility or employment. Years 7–9 learning is an early foundation; any later credential may require substantial study, experience or local approval.
Vocabulary: like terms · coefficient · variable part · power
Retrieve previous learning
How many apples are 3 apples plus 4 apples?
Check: 7 apples.
Learn the concept
The terms 3x and 4x are like terms because both count x-units; their sum is 7x. The terms 3x and 4x² count different units and cannot be combined into 7x or 7x². Similarly 2ab and 5ba are like terms because ab = ba.
Like terms have the same letters raised to the same powers, even when written in a different order. A constant has no variable part, so 6 and −2 are like terms. Identify the complete signed term before collecting.
Worked model
In 3x + 2y − 5x + 4y, group 3x and −5x.
Group 2y and 4y separately.
The two variable parts differ, so do not combine x with y.
Guided practice
Which terms in 4a² + 3a − 7a² + 2 are like 4a²?
Hint: Compare both the letter and its exponent.
Check the guided answer
Only −7a² is like 4a²; 3a has a different power and 2 is a constant.
Independent practice
Write your own response to every question before viewing the model answers. Your writing stays in this page session; this activity does not submit, store or grade it. Avoid including private information.
Find and correct a misconception
“Any terms containing the same letter are like terms.”
Correction: The entire variable part, including every exponent, must match.
Extend and reflect
Are 3a²b and −ba² like terms?
Guidance: Yes: multiplication is commutative, so both have variable part a²b.
Take the end-of-unit checkWhere this lesson could lead · Mathematics GCSE → Daskerel Mathematical Sciences
This lesson practises: Group terms with the same variable powers. Quantitative reasoning supports later mathematical, data and engineering study.
Next school subject:Mathematics GCSE. Check the subject and examination board that fit your school.
Later credential exploration: No subject-specific professional credential is mapped from this lesson. Explore the credential catalogue after choosing a later specialism.
This is an exploratory route, not a promise of admission, a qualification, certification eligibility or employment. Years 7–9 learning is an early foundation; any later credential may require substantial study, experience or local approval.
Year 7 · Algebra · original lesson pack
DASKEREL beta · internal AI review pending
Collect like terms without changing an expression's value
Vocabulary: simplify · equivalent · collect · signed term
Retrieve previous learning
What is 5x − 2x?
Check: 3x.
Learn the concept
Collecting like terms changes the form, not the value. For 5a − 2b − 8a + 6b, combine the a terms as −3a and the b terms as 4b, giving −3a + 4b. The minus sign belongs to each term after it.
A substitution check can catch a sign error. At a = 2 and b = 3, the original is 10 − 6 − 16 + 18 = 6; the simplified form is −6 + 12 = 6. One check does not prove equivalence for every input, but the collection law does.
Worked model
Rewrite 7p − 4 + 2p + 9 as (7p + 2p) + (−4 + 9).
Add the coefficients: 9p + 5.
At p = 1, both forms give 14.
Guided practice
Simplify 8x − 3y − 11x + 5y.
Hint: Group x terms and y terms with their signs.
Check the guided answer
(8 − 11)x + (−3 + 5)y = −3x + 2y.
Independent practice
Write your own response to every question before viewing the model answers. Your writing stays in this page session; this activity does not submit, store or grade it. Avoid including private information.
Find and correct a misconception
“Subtracting a term removes its negative sign when terms are reordered.”
Correction: Move each signed term intact; −4 and −9 sum to −13.
Extend and reflect
Show 2x + 3y + 5x − y = 7x + 2y for every x and y.
Guidance: Use commutativity and associativity to group like terms; no particular substitution is needed.
Take the end-of-unit checkWhere this lesson could lead · Mathematics GCSE → Daskerel Mathematical Sciences
This lesson practises: Simplify sums of signed terms. Quantitative reasoning supports later mathematical, data and engineering study.
Next school subject:Mathematics GCSE. Check the subject and examination board that fit your school.
Later credential exploration: No subject-specific professional credential is mapped from this lesson. Explore the credential catalogue after choosing a later specialism.
This is an exploratory route, not a promise of admission, a qualification, certification eligibility or employment. Years 7–9 learning is an early foundation; any later credential may require substantial study, experience or local approval.
Three copies of (x + 4) contain three x-units and twelve ones: 3(x + 4) = 3x + 12. Multiplication applies to every term in the bracket. Check at x = 2: both sides give 18.
For −2(3x − 5), multiply −2 by 3x and by −5 separately to get −6x + 10. A useful area model labels the signed lengths algebraically, but do not treat a negative geometric area as a physical area; use the arithmetic law for signed numbers.
Worked model
In 4(2a − 3), multiply 4 by 2a to get 8a.
Multiply 4 by −3 to get −12.
Write 8a − 12; at a = 2, both forms equal 4.
Guided practice
Expand −3(y + 4).
Hint: Multiply −3 by both y and 4.
Check the guided answer
−3y − 12.
Independent practice
Write your own response to every question before viewing the model answers. Your writing stays in this page session; this activity does not submit, store or grade it. Avoid including private information.
Find and correct a misconception
“The multiplier applies only to the first term in a bracket.”
Correction: The distributive law multiplies each term inside the bracket.
Extend and reflect
Factorise 12x − 20 using the inverse of expansion.
Guidance: Both terms contain 4, so 12x − 20 = 4(3x − 5).
Take the end-of-unit checkWhere this lesson could lead · Mathematics GCSE → Daskerel Mathematical Sciences
This lesson practises: Expand a constant times a bracket. Quantitative reasoning supports later mathematical, data and engineering study.
Next school subject:Mathematics GCSE. Check the subject and examination board that fit your school.
Later credential exploration: No subject-specific professional credential is mapped from this lesson. Explore the credential catalogue after choosing a later specialism.
This is an exploratory route, not a promise of admission, a qualification, certification eligibility or employment. Years 7–9 learning is an early foundation; any later credential may require substantial study, experience or local approval.
Vocabulary: monomial · coefficient · power · distribute
Retrieve previous learning
What is x × x and what is 2 × 3?
Check: x² and 6.
Learn the concept
To expand 2x(3x + 4), multiply 2x by each term: 2x × 3x = 6x² and 2x × 4 = 8x. Thus the result is 6x² + 8x. The power rises because x × x = x², not because the coefficients are added.
A negative term changes signs. For −3a(2a − 5), the products are −6a² and +15a, giving −6a² + 15a. At a = 2, both original and expansion equal −3 × 2 × (4 − 5) = 6.
Worked model
Write 4y(y − 3) as 4y × y − 4y × 3.
Calculate 4y² − 12y.
At y = 2, original 8(−1) and expanded 16 − 24 both equal −8.
Guided practice
Expand 5m(2m + 1).
Hint: Multiply 5m by each term; m × m = m².
Check the guided answer
10m² + 5m.
Independent practice
Write your own response to every question before viewing the model answers. Your writing stays in this page session; this activity does not submit, store or grade it. Avoid including private information.
Find and correct a misconception
“Multiplying x by x leaves x.”
Correction: x × x = x²; count the repeated variable factors.
Extend and reflect
Expand −a²(2a − 3).
Guidance: Multiply each term: −2a³ + 3a².
Take the end-of-unit checkWhere this lesson could lead · Mathematics GCSE → Daskerel Mathematical Sciences
This lesson practises: Multiply coefficients and variable powers. Quantitative reasoning supports later mathematical, data and engineering study.
Next school subject:Mathematics GCSE. Check the subject and examination board that fit your school.
Later credential exploration: No subject-specific professional credential is mapped from this lesson. Explore the credential catalogue after choosing a later specialism.
This is an exploratory route, not a promise of admission, a qualification, certification eligibility or employment. Years 7–9 learning is an early foundation; any later credential may require substantial study, experience or local approval.
Vocabulary: expand · collect · equivalent · signed product
Retrieve previous learning
Expand 2(x + 3).
Check: 2x + 6.
Learn the concept
In 2(x + 3) + 3(x − 1), expand each bracket before collecting: 2x + 6 + 3x − 3 = 5x + 3. The plus between products means both expanded expressions contribute to the sum.
Subtraction needs extra care. For 4(y + 2) − 2(y − 5), first write 4y + 8 − (2y − 10). The entire second product is subtracted, so 4y + 8 − 2y + 10 = 2y + 18. Substituting y = 1 gives 20 in both forms.
Worked model
Expand 3(2a − 1) + 2(a + 4) to 6a − 3 + 2a + 8.
Collect a terms and constants separately.
Obtain 8a + 5.
Guided practice
Simplify 2(p + 5) + 4(p − 2).
Hint: Expand both products before grouping.
Check the guided answer
2p + 10 + 4p − 8 = 6p + 2.
Independent practice
Write your own response to every question before viewing the model answers. Your writing stays in this page session; this activity does not submit, store or grade it. Avoid including private information.
Find and correct a misconception
“A minus sign between products changes only the first term of the second bracket.”
Correction: Subtract the entire product, or distribute a negative multiplier to every term.
Extend and reflect
Simplify −2(3x − 4) − 3(2x + 1).
Guidance: The expansion is −6x + 8 − 6x − 3 = −12x + 5.
Take the end-of-unit checkWhere this lesson could lead · Mathematics GCSE → Daskerel Mathematical Sciences
This lesson practises: Expand each product accurately. Quantitative reasoning supports later mathematical, data and engineering study.
Next school subject:Mathematics GCSE. Check the subject and examination board that fit your school.
Later credential exploration: No subject-specific professional credential is mapped from this lesson. Explore the credential catalogue after choosing a later specialism.
This is an exploratory route, not a promise of admission, a qualification, certification eligibility or employment. Years 7–9 learning is an early foundation; any later credential may require substantial study, experience or local approval.
Year 7 · Algebra · original lesson pack
DASKEREL beta · internal AI review pending
Choose an efficient order for equivalent expressions
Vocabulary: factor · equivalent · distributive law · efficiency
Retrieve previous learning
Simplify 3x + 2x.
Check: 5x.
Learn the concept
In 3(2x + 5) + 2(2x + 5), both products share the same bracket. Treat that bracket as one quantity B: 3B + 2B = 5B. The compact result 5(2x + 5) can then expand to 10x + 25 if needed. This is the distributive law in reverse.
Efficiency does not license changing grouping. For 3(x + 2) + 2(x − 2), the brackets differ; calling both B would be wrong. Expand to 3x + 6 + 2x − 4 = 5x + 2, or use 5x plus the separately signed constants.
Worked model
Identify repeated bracket (a − 4) in 7(a − 4) − 2(a − 4).
Write your own response to every question before viewing the model answers. Your writing stays in this page session; this activity does not submit, store or grade it. Avoid including private information.
Find and correct a misconception
“Any two brackets containing x can be combined as identical units.”
Correction: They must be exactly the same expression before their coefficients can be collected directly.
Extend and reflect
Simplify a(x + 2) + b(x + 2).
Guidance: Factor the common bracket to (a + b)(x + 2), valid for all a, b and x.
Take the end-of-unit checkWhere this lesson could lead · Mathematics GCSE → Daskerel Mathematical Sciences
This lesson practises: Simplify a shared structure before expanding. Quantitative reasoning supports later mathematical, data and engineering study.
Next school subject:Mathematics GCSE. Check the subject and examination board that fit your school.
Later credential exploration: No subject-specific professional credential is mapped from this lesson. Explore the credential catalogue after choosing a later specialism.
This is an exploratory route, not a promise of admission, a qualification, certification eligibility or employment. Years 7–9 learning is an early foundation; any later credential may require substantial study, experience or local approval.
Vocabulary: highest common factor · coefficient · power · factor
Retrieve previous learning
What is the highest common factor of 12 and 18?
Check: 6.
Learn the concept
The terms 12x² and 18x each contain a factor 6x: 12x² = 6x × 2x and 18x = 6x × 3. The numerical HCF is 6, while the shared algebraic part is one x, not x² because 18x has only one x factor.
For 8a²b and 12ab³, the numerical HCF is 4 and the shared letters are a and b, so the HCF is 4ab. Dividing gives 2a and 3b², which multiply back to the original terms.
Worked model
Find HCF(15, 25) = 5.
For 15p³ and 25p², the smaller p power is p².
The algebraic HCF is 5p²; check factors 3p and 5.
Guided practice
Find the HCF of 18m²n and 24mn².
Hint: Use the smaller exponent for each shared letter.
Check the guided answer
6mn, since the numerical HCF is 6 and each term has at least one m and one n.
Independent practice
Write your own response to every question before viewing the model answers. Your writing stays in this page session; this activity does not submit, store or grade it. Avoid including private information.
Find and correct a misconception
“The HCF uses the largest power seen in either term.”
Correction: A common factor must divide every term; choose the lowest shared power.
Extend and reflect
Find the HCF of 24a³b², 36a²b and 60ab³.
Guidance: The coefficient HCF is 12 and minimum powers are a¹b¹, so 12ab.
Take the end-of-unit checkWhere this lesson could lead · Mathematics GCSE → Daskerel Mathematical Sciences
This lesson practises: Find the HCF of coefficients and variable powers. Quantitative reasoning supports later mathematical, data and engineering study.
Next school subject:Mathematics GCSE. Check the subject and examination board that fit your school.
Later credential exploration: No subject-specific professional credential is mapped from this lesson. Explore the credential catalogue after choosing a later specialism.
This is an exploratory route, not a promise of admission, a qualification, certification eligibility or employment. Years 7–9 learning is an early foundation; any later credential may require substantial study, experience or local approval.
Vocabulary: factorise · common factor · expand · equivalent
Retrieve previous learning
Expand 3(x + 4).
Check: 3x + 12.
Learn the concept
Factorising rewrites a sum as a product. For 12x + 18, the highest common numerical factor is 6, giving 6(2x + 3). Re-expand to check: 6 × 2x + 6 × 3 = 12x + 18.
With algebraic factors, 15a² − 10a contains 5a in both terms. Divide each term by 5a to obtain 5a(3a − 2). Retain the negative sign in the bracket and re-expand. For a = 0, both forms are zero; the algebraic law establishes equivalence for all a.
Worked model
Find the HCF of 14y² and 21y as 7y.
Divide 14y² by 7y to get 2y and 21y by 7y to get 3.
Write 14y² + 21y = 7y(2y + 3), then expand to check.
Guided practice
Factorise 8p − 12 using the highest common factor.
Hint: Both coefficients divide by 4.
Check the guided answer
4(2p − 3); expanding gives 8p − 12.
Independent practice
Write your own response to every question before viewing the model answers. Your writing stays in this page session; this activity does not submit, store or grade it. Avoid including private information.
Find and correct a misconception
“The common factor is removed only from the first term.”
Correction: Divide every term by the extracted factor; re-expansion checks the result.
Extend and reflect
Can 6x² + 9x be factorised with 3x even if x = 0?
Guidance: Yes, 3x(2x + 3) is an identity; avoid deriving it by dividing both sides by x at x = 0.
Take the end-of-unit checkWhere this lesson could lead · Mathematics GCSE → Daskerel Mathematical Sciences
This lesson practises: Take out a common factor. Quantitative reasoning supports later mathematical, data and engineering study.
Next school subject:Mathematics GCSE. Check the subject and examination board that fit your school.
Later credential exploration: No subject-specific professional credential is mapped from this lesson. Explore the credential catalogue after choosing a later specialism.
This is an exploratory route, not a promise of admission, a qualification, certification eligibility or employment. Years 7–9 learning is an early foundation; any later credential may require substantial study, experience or local approval.
Two fictional club plans charge A = £12 + £4 per visit and B = £30 + £2 per visit. For n visits, costs are A(n) = 12 + 4n and B(n) = 30 + 2n. Equal cost requires 12 + 4n = 30 + 2n, so 2n = 18 and n = 9. Substitute: both cost £48.
The algebraic solution must fit the situation: visits are nonnegative whole numbers. For fewer than nine visits, A is cheaper (at n = 5: £32 versus £40); for more than nine, B is cheaper (at n = 12: £60 versus £54). The model assumes exactly these fees and no other charges.
Worked model
Let n be the number of visits and state n is a nonnegative integer.
Write costs 12 + 4n and 30 + 2n.
Solve 12 + 4n = 30 + 2n to find n = 9.
Check both at n = 9: £48.
Guided practice
Plan C costs £5 plus £3 per visit and D costs £17 plus £1 per visit. When do they cost the same?
Hint: Write 5 + 3n = 17 + n.
Check the guided answer
2n = 12, so n = 6; both cost £23.
Independent practice
Write your own response to every question before viewing the model answers. Your writing stays in this page session; this activity does not submit, store or grade it. Avoid including private information.
Find and correct a misconception
“The plan with the lower fixed fee is always cheaper.”
Correction: The variable rate also matters; solve or compare costs at the relevant quantity.
Extend and reflect
What changes if visits can be cancelled but the fixed fee remains?
Guidance: The formulas still apply to completed visits, but refund or cancellation terms must be added before claiming a real-life cost.
Take the end-of-unit checkWhere this lesson could lead · Mathematics GCSE → Daskerel Mathematical Sciences
This lesson practises: Translate a context into expressions. Quantitative reasoning supports later mathematical, data and engineering study.
Next school subject:Mathematics GCSE. Check the subject and examination board that fit your school.
Later credential exploration: No subject-specific professional credential is mapped from this lesson. Explore the credential catalogue after choosing a later specialism.
This is an exploratory route, not a promise of admission, a qualification, certification eligibility or employment. Years 7–9 learning is an early foundation; any later credential may require substantial study, experience or local approval.
Original DASKEREL written unit check · controlled beta
Year 7 expressions and equations: written unit check
Use generalisation, notation, substitution, expansion and factorisation. Explain each step and check equations by substituting the solution. Attempt each question before opening its model reasoning. This is editorial practice, not a validated school test or a verified attainment result.
Independent practice
Write your own response to every question before viewing the model answers. Your writing stays in this page session; this activity does not submit, store or grade it. Avoid including private information.
Written self-checks are editorial practice. Practical and performance competence needs observation; qualified academic and accessibility review remain pending.