What is algebra?
Algebra is its own strand in Year 6: simple formulae, number sequences, missing number problems and pairs of numbers with two unknowns. Below: what it means, a worked example, the mistake to watch for and an 11+ question.
The answer
Algebra uses letters to stand for numbers we do not know yet, or for numbers that can change.
What it means
In n + 7 = 12, the letter n stands for a missing number. Here n = 5, because 5 + 7 = 12.
3a means 3 × a. If a = 4, then 3a = 12.
An equation is like a balance: whatever you do to one side, do to the other, and it stays balanced.
A worked example
Solve 2x + 5 = 17
- Take 5 from both sides: 2x = 12.
- Divide both sides by 2: x = 6.
- Check: 2 × 6 + 5 = 17.
The common mistake
Reading 3a as a two-digit number. If a = 4, 3a is 3 × 4 = 12, not 34.
How it comes up in the 11+
If 4y − 3 = 25, what is y?
Answer: y = 7
- Add 3 to both sides: 4y = 28.
- Divide both sides by 4: y = 7.
- Check: 4 × 7 − 3 = 25.
Try it yourself
It opens on 2x + 5 = 17, the worked example. Step through it by doing the same thing to both sides, then check the answer.
An equation stays balanced when you do the same thing to both sides.
Related words and practice
More maths words
Questions parents ask
Is algebra in the 11+?
Yes. Expect missing number equations, simple formulae, number sequences and puzzles with two unknowns, all at a Year 6 level.
Why use letters instead of a box or a question mark?
Letters do the same job, but you can use more than one: in a + b = 10, a and b are two different unknowns.
Knowing the words is half of an 11+ maths question
11+ papers use maths vocabulary without explaining it. The free diagnostic checks maths, English and both kinds of reasoning, and shows what to practise next. No card is required.