Think of a Number Puzzles Worksheet
The trick (Undo the steps): Going forwards: do the steps in order. Going backwards: start from the result and undo each step, last one first. Undo + with −, × with ÷, and doubling with halving.
NameDateTime takenScore ___ / 40
- 1.I thought of a number, multiplied it by 3 and added 1. I got 16. What was my number?
- 2.Magic trick! Think of 9. Double it, add 12, halve it, then take away 9. What number do you get?
- 3.Think of 5. Multiply it by 2, then add 5. What number do you end with?
- 4.I thought of a number, added 8 and then doubled it. I got 28. What was my number?
- 5.Magic trick! Think of 6. Double it, add 18, halve it, then take away 6. What number do you get?
- 6.I thought of a number, multiplied it by 4 and added 6. I got 34. What was my number?
- 7.I thought of a number, added 6 and then doubled it. I got 24. What was my number?
- 8.Magic trick! Think of 11. Double it, add 8, halve it, then take away 11. What number do you get?
- 9.I thought of a number, added 8 and then doubled it. I got 36. What was my number?
- 10.Think of 9. Multiply it by 5, then add 7. What number do you end with?
- 11.I thought of a number, added 6 and then doubled it. I got 46. What was my number?
- 12.Think of 10. Multiply it by 2, then add 8. What number do you end with?
- 13.Think of 2. Multiply it by 2, then add 4. What number do you end with?
- 14.I thought of a number, multiplied it by 4 and added 6. I got 62. What was my number?
- 15.Think of 6. Multiply it by 3, then add 6. What number do you end with?
- 16.Magic trick! Think of 7. Double it, add 4, halve it, then take away 7. What number do you get?
- 17.Magic trick! Think of 3. Double it, add 10, halve it, then take away 3. What number do you get?
- 18.I thought of a number, added 6 and then doubled it. I got 42. What was my number?
- 19.I thought of a number, multiplied it by 2 and added 2. I got 22. What was my number?
- 20.I thought of a number, multiplied it by 3 and added 9. I got 51. What was my number?
- 21.Magic trick! Think of 17. Double it, add 10, halve it, then take away 17. What number do you get?
- 22.Think of 12. Multiply it by 3, then add 8. What number do you end with?
- 23.Think of 14. Multiply it by 2, then add 9. What number do you end with?
- 24.Think of 8. Multiply it by 3, then add 9. What number do you end with?
- 25.Think of 10. Multiply it by 2, then add 3. What number do you end with?
- 26.Think of 9. Multiply it by 2, then add 2. What number do you end with?
- 27.I thought of a number, added 8 and then doubled it. I got 26. What was my number?
- 28.I thought of a number, multiplied it by 2 and added 4. I got 28. What was my number?
- 29.Think of 5. Multiply it by 2, then add 4. What number do you end with?
- 30.Think of 5. Multiply it by 4, then add 7. What number do you end with?
- 31.Think of 4. Multiply it by 3, then add 5. What number do you end with?
- 32.I thought of a number, added 7 and then doubled it. I got 26. What was my number?
- 33.Think of 2. Multiply it by 3, then add 1. What number do you end with?
- 34.I thought of a number, multiplied it by 2 and added 2. I got 12. What was my number?
- 35.I thought of a number, multiplied it by 2 and added 8. I got 30. What was my number?
- 36.I thought of a number, multiplied it by 4 and added 7. I got 15. What was my number?
- 37.I thought of a number, multiplied it by 4 and added 4. I got 20. What was my number?
- 38.Magic trick! Think of 7. Double it, add 14, halve it, then take away 7. What number do you get?
- 39.Think of 11. Multiply it by 2, then add 9. What number do you end with?
- 40.I thought of a number, added 3 and then doubled it. I got 26. What was my number?
Answer key
- 5
- 6
- 15
- 6
- 9
- 7
- 6
- 4
- 10
- 52
- 17
- 28
- 8
- 14
- 24
- 2
- 5
- 15
- 10
- 14
- 5
- 44
- 37
- 33
- 23
- 20
- 5
- 12
- 14
- 27
- 17
- 6
- 7
- 5
- 11
- 2
- 4
- 7
- 31
- 10
Free maths tricks lessons, practice and worksheets at talentjr.in/maths-tricks