1 · Variables & Expressions
Use letters to stand for unknown numbers and turn words into algebraic expressions.
What your child learns
- A variable is a letter that stands for a number
- 3n means 3 × n
- Translate phrases like '5 less than n' into n − 5
Example
'Twice a number plus 4' → 2n + 4.
Mini lesson: Variables & Expressions
Goal: Use a letter to stand for a number you don’t know yet, and turn words into maths.
- 3x means 3 × x (we leave out the × sign).
- x ÷ 4 can also be written x/4.
- “more than” → add, “less than” → subtract (watch the order!), “times”/“product” → multiply.
Worked example
Write “7 less than a number n”.
- “less than” means subtract.
- We start with n and take 7 away.
- Answer: n − 7 (not 7 − n).
Common mistakes
- Writing “5 less than n” as 5 − n.
- Reading 3x as “thirty-something” instead of 3 × x.
Practice questions
A taste of the questions in BloomTracks – the app makes fresh ones every time and adjusts the level as your child answers.
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Question 1 · Level 1
Which expression means “7 less than a”?
- a + 7
- 7a
- a − 7
- 7 − a
Show the answer
Answer: a − 7
“7 less than a” is written a − 7.
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Question 2 · Level 3
Which expression means “n squared, plus 4”?
- n + 4²
- (n + 4)²
- n² + 4
- 2n + 4
Show the answer
Answer: n² + 4
“n squared, plus 4” → n² + 4.
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Question 3 · Level 5
Cinema tickets cost $9 each and popcorn costs $5. Write the total cost for t tickets and one popcorn. (Use the letter t.)
Show the answer
Answer: 9t+5
9t + 5 (other equivalent forms are fine too).
Try it at home
Describe a real situation with a letter: 'If each ticket costs $3, t tickets cost 3t'.
Key takeaway
Watch the order: '5 less than n' is n − 5, not 5 − n.
Practise 1 · variables & expressions with Bloomie
Bloomie reads every question aloud, listens to spoken answers and adapts the difficulty one question at a time.