Understanding that a letter can represent an unknown number, and substituting values into simple expressions.
Where your child meets this in real life: Writing formulas, understanding spreadsheet cells, generalising patterns
Each SEAG paper has 28 maths questions. Questions 29 to 50 are multiple choice with five possible answers, and questions 51 to 56 need a short written answer. With 56 questions in 60 minutes across English and maths, that is about a minute per question.
SEAGReady breaks letters for unknowns into 3 steps, taught in order so each skill builds on the last.
Building block, not tested on its own
Replace a letter with a given value and calculate the result using explicit operation signs
Extension, not needed for SEAG
Evaluate expressions using algebraic notation where multiplication signs are omitted (e.g., 4n means 4 times n)
Building block, not tested on its own
Evaluate expressions where the same letter appears multiple times, using the same value consistently
Try three free questions from our letters for unknowns course. They start easy and get harder, so you can see where your child's confidence runs out. If they manage the last one without a hint, this topic is probably secure. If not, the steps above show where to start.
Ethan has n stickers in his album. He gets 8 more stickers from his friend. If n = 6, how many stickers does Ethan have now?
Megan buys n notebooks. Each costs £7. If n = 6, find the total cost using 7n.
A rectangle has width w cm and length w + 3 cm. Its perimeter is w + w + (w + 3) + (w + 3). If w = 5, what is the perimeter?
This is the exact interactive worked example your child sees in SEAGReady. Step through it and watch the method build up.
Isla has n marbles in her bag. She finds 7 more marbles in the garden.
If n = 5, how many marbles does Isla have now?
n + 7 when n = 5
The letter n stands for a number we know
Step 1 of 4
Isla has n marbles in her bag. She finds 7 more marbles in the garden.
If n = 5, how many marbles does Isla have now?
Isla has 12 marbles now.
The key insight: A letter is just a placeholder for a number - once you know the number, swap it in!
Common mix-up: Thinking n means 'nothing' and writing 0 + 7 = 7. The letter n is not zero - it represents the specific number we're given (in this case, 5).
These are the misconceptions we see most often in letters for unknowns, including the ones our practice questions are specifically designed to catch.
Sitting the SEAG test this November? Read our last-month revision plan, Paper 1 vs Paper 2 and test day guide.
SEAGReady finds the exact step where your child gets stuck, teaches it with worked examples like the one above, and brings it back for review so it sticks.
Free to start · no card needed