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, added 9 and then doubled it. I got 58. What was my number?
- 2.I thought of a number, multiplied it by 2 and added 7. I got 13. What was my number?
- 3.I thought of a number, added 1 and then doubled it. I got 28. What was my number?
- 4.Magic trick! Think of 12. Double it, add 8, halve it, then take away 12. What number do you get?
- 5.Magic trick! Think of 13. Double it, add 4, halve it, then take away 13. What number do you get?
- 6.Magic trick! Think of 6. Double it, add 8, halve it, then take away 6. What number do you get?
- 7.I thought of a number, added 9 and then doubled it. I got 40. What was my number?
- 8.I thought of a number, multiplied it by 2 and added 6. I got 20. What was my number?
- 9.I thought of a number, added 5 and then doubled it. I got 38. What was my number?
- 10.I thought of a number, multiplied it by 2 and added 6. I got 22. What was my number?
- 11.I thought of a number, added 8 and then doubled it. I got 30. What was my number?
- 12.I thought of a number, added 9 and then doubled it. I got 24. What was my number?
- 13.Magic trick! Think of 18. Double it, add 18, halve it, then take away 18. What number do you get?
- 14.I thought of a number, added 3 and then doubled it. I got 14. What was my number?
- 15.Magic trick! Think of 19. Double it, add 14, halve it, then take away 19. What number do you get?
- 16.Think of 11. Multiply it by 4, then add 5. What number do you end with?
- 17.I thought of a number, added 6 and then doubled it. I got 34. What was my number?
- 18.Magic trick! Think of 16. Double it, add 14, halve it, then take away 16. What number do you get?
- 19.Magic trick! Think of 15. Double it, add 6, halve it, then take away 15. What number do you get?
- 20.I thought of a number, multiplied it by 4 and added 8. I got 24. What was my number?
- 21.Think of 2. Multiply it by 4, then add 2. What number do you end with?
- 22.Think of 4. Multiply it by 4, then add 9. What number do you end with?
- 23.I thought of a number, added 8 and then doubled it. I got 54. What was my number?
- 24.Magic trick! Think of 9. Double it, add 14, halve it, then take away 9. What number do you get?
- 25.Think of 13. Multiply it by 3, then add 6. What number do you end with?
- 26.I thought of a number, added 2 and then doubled it. I got 12. What was my number?
- 27.I thought of a number, added 4 and then doubled it. I got 28. What was my number?
- 28.Magic trick! Think of 12. Double it, add 18, halve it, then take away 12. What number do you get?
- 29.I thought of a number, added 7 and then doubled it. I got 34. What was my number?
- 30.I thought of a number, added 9 and then doubled it. I got 46. What was my number?
- 31.I thought of a number, multiplied it by 5 and added 6. I got 21. What was my number?
- 32.I thought of a number, multiplied it by 5 and added 1. I got 41. What was my number?
- 33.I thought of a number, multiplied it by 5 and added 6. I got 46. What was my number?
- 34.I thought of a number, added 3 and then doubled it. I got 26. What was my number?
- 35.I thought of a number, added 4 and then doubled it. I got 38. What was my number?
- 36.I thought of a number, multiplied it by 2 and added 5. I got 21. What was my number?
- 37.I thought of a number, added 7 and then doubled it. I got 20. What was my number?
- 38.Think of 3. Multiply it by 4, then add 7. What number do you end with?
- 39.I thought of a number, added 4 and then doubled it. I got 18. What was my number?
- 40.Think of 12. Multiply it by 2, then add 4. What number do you end with?
Answer key
- 20
- 3
- 13
- 4
- 2
- 4
- 11
- 7
- 14
- 8
- 7
- 3
- 9
- 4
- 7
- 49
- 11
- 7
- 3
- 4
- 10
- 25
- 19
- 7
- 45
- 4
- 10
- 9
- 10
- 14
- 3
- 8
- 8
- 10
- 15
- 8
- 3
- 19
- 5
- 28
Free maths tricks lessons, practice and worksheets at talentjr.in/maths-tricks