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
SEAGReady breaks letters for unknowns into 3 steps, taught in order so each skill builds on the last.
Replace a letter with a given value and calculate the result using explicit operation signs
Evaluate expressions using algebraic notation where multiplication signs are omitted (e.g., 4n means 4 times n)
Evaluate expressions where the same letter appears multiple times, using the same value consistently
Three free sample questions from our letters for unknowns course. Every question comes with a full explanation, and hints that guide without giving the answer away.
Sean has n stickers in his album. He gets 8 more stickers from his friend. If n = 6, how many stickers does Sean have now?
Answer: A. 14 stickers
The letter n represents Sean's starting stickers. We are told n = 6, so Sean starts with 6 stickers. He gets 8 more: 6 + 8 = 14 stickers.
Stuck? Start here: The letter n represents how many stickers Sean started with. What number does n stand for?
Oisin works at a cafe for h hours and earns £5 per hour. His pay is written as 5h. If h = 3, how much does he earn?
Answer: A. £15
5h means 5 x h. Replace h with 3: 5h = 5 x 3 = £15
Stuck? Start here: Remember: when a number is written next to a letter, it means multiply.
Ciara buys two identical pens costing £n each, plus a ruler costing £2. If n = 3, what is the total cost?
Answer: A. £8
The letter n appears twice for the two identical pens. Both n's have the same value: 3. n + n + 2 = 3 + 3 + 2 = £8
Stuck? Start here: The same letter n appears twice - for both pens. They must have the same value.
This is the exact interactive worked example your child sees in SEAGReady. Step through it and watch the method build up.
Ciara has n marbles in her bag. She finds 7 more marbles in the garden.
If n = 5, how many marbles does Ciara have now?
n + 7 when n = 5
Step 1 of 4
Ciara has n marbles in her bag. She finds 7 more marbles in the garden.
If n = 5, how many marbles does Ciara have now?
Ciara has 12 marbles now.
The key insight: A letter is just a placeholder for a number - once you know the number, swap it in!
Watch out: 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.
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.