How it works
Undo the one operation, and do the same to both sides.
6 × ? = 48: undo times by dividing, 48 ÷ 6 = 8.
x + 1.75 = 2.55: undo adding by taking away: 2.55 − 1.75 = 0.80.
Worked examples
A times
- 6 × ? = 48.
- Undo the times by dividing: 48 ÷ 6 = 8.
- The missing number is 8.
A fraction
- 1/8 × ? = 3.
- Undo by dividing by 1/8, which is times 8: 3 × 8 = 24.
- The missing number is 24.
An add
- Ava had some water and poured in 1.75 liters more. Now there are 2.55 liters.
- Undo the adding: 2.55 − 1.75 = 0.80.
- She had 0.80 liters to start.
A taste of the worksheet
These are the first problems of set A. The printable sheet has many more, with an answer key.
- The tape shows x + 9 = 15. What is x? Answer: ___
- Mia had some stickers. She got 8 more. Now she has 20. How many did she have at first? Answer: ___
- Which equation fits this tape?
- The tape shows 4x = 20. Four equal parts make 20. What is x? Answer: ___
- What undoes adding 11?