5 · One-Step Equations
Solve equations that need just one inverse operation.
What your child learns
- Undo + with −, and − with +
- Undo × with ÷, and ÷ with ×
- Check by substituting the answer back
Example
6x = 42 → divide both sides by 6 → x = 7.
Mini lesson: One-Step Equations
Goal: Solve equations that need one inverse operation.
Ask: “What is being done to x?” Then do the opposite to both sides.
- x + 6 = 10 → subtract 6
- x − 6 = 10 → add 6
- 6x = 30 → divide by 6
- x ÷ 6 = 5 → multiply by 6
Worked example
Solve 7x = 42.
- x is multiplied by 7.
- Divide both sides by 7: x = 42 ÷ 7
- x = 6. Check: 7 × 6 = 42 ✔
Common mistakes
- Subtracting 7 instead of dividing by 7.
- Forgetting to check the answer.
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
Solve: x + 5 = 12
Show the answer
Answer: 7
Subtract 5 on both sides: x = 7.
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Question 2 · Level 3
Solve: 9x = 108
Show the answer
Answer: 12
Divide by 9 on both sides: x = 12.
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Question 3 · Level 5
Solve: a − 3 = −15
Show the answer
Answer: −12
Add 3 on both sides: a = −12.
Try it at home
'I'm thinking of a number; I added 9 and got 15 — what was it?'
Key takeaway
Ask what is being done to x, then do the opposite.
Practise 5 · one-step equations with Bloomie
Bloomie reads every question aloud, listens to spoken answers and adapts the difficulty one question at a time.