Home → Curriculum Hub → Maths Lessons → Schemes of Work → Two-Year IGCSE Higher → Algebraic Expressions
Algebraic Expressions is the first algebra unit in the IGCSE Mathematics Higher scheme of work. It introduces important skills that students will use throughout the course, including expanding and factorising expressions.
Students learn to take out common factors, expand two and three brackets and collect like terms. They then use these skills in reverse to factorise quadratic expressions, including quadratics where the coefficient of (x2) is greater than 1.
By the end of this unit students will be able to:
Students should be secure with the following before beginning this unit.
The factor outside the bracket is the largest number and the lowest power that divides every term. 6x3 − 9x2 is 3x2(2x − 3), not 3x(2x2 − 3x). Check by expanding.
For two brackets, four products appear, then the like terms are collected. A missing inner or outer product leaves the linear term wrong. For three binomials, expand two first, then multiply the quadratic by the third bracket.
For x2 + bx + c, find two numbers that multiply to c and add to b. Expand to check before the brackets are declared. A pair that multiplies to c but does not add to b is not a factorisation.
For ax2 + bx + c, the numbers in the brackets must multiply to ac and still give the linear term when expanded. Factorising by grouping, or by trying pairs that include the factors of a, both work. Leaving a outside and factorising x2 + bx + c as if a were 1 does not.
| Misconception | Teaching focus |
|---|---|
| Taking out a common factor that is not the highest power, so a power of x remains in every term inside. | Ask which power of x divides every term. That lowest power, with the numerical HCF, goes outside. |
| Expanding two brackets as the product of the first terms plus the product of the last terms, and missing the two cross products. | Write a two-by-two grid, or list first, outer, inner, last, then collect the middle pair. |
| When expanding three brackets, multiplying only the end terms of the third bracket by the quadratic. | Expand the first pair fully. Then multiply every term of that quadratic by each term of the third bracket. |
| Choosing a factor pair that multiplies to c but does not add to b. | Expand the proposed brackets before moving on. If the linear term is wrong, the pair is not a factorisation. |
| Factorising ax2 + bx + c by ignoring a, then tacking a on the front. | The constants in the brackets must multiply to ac. Expand to check the coefficient of x2 as well as the constant. |
Every lesson in this unit is already built. A Mr Mathematics membership gives you the presentation, worksheet, question generator and video tutorial for all five lessons, alongside the full Key Stage 3, GCSE, IGCSE and A-Level libraries.
A school membership covers every teacher in your department, so the whole scheme of work is resourced from one subscription.
A research-backed case exploring why over-reliance on automated math homework platforms and repetitive worksheets lowers student expectations, and how departments can build genuine mathematical thinking.
How to teach converting between fractions, decimals and percentages.
Four problem solving lessons to develop student’s mathematical reasoning and communication skills.