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 7 and then doubled it. I got 46. What was my number?
- 2.Think of 12. Multiply it by 2, then add 8. What number do you end with?
- 3.Think of 13. Multiply it by 2, then add 9. What number do you end with?
- 4.Magic trick! Think of 16. Double it, add 14, halve it, then take away 16. What number do you get?
- 5.I thought of a number, multiplied it by 5 and added 6. I got 26. What was my number?
- 6.I thought of a number, multiplied it by 4 and added 6. I got 66. What was my number?
- 7.Magic trick! Think of 20. Double it, add 6, halve it, then take away 20. What number do you get?
- 8.I thought of a number, multiplied it by 2 and added 4. I got 26. What was my number?
- 9.Think of 10. Multiply it by 4, then add 7. What number do you end with?
- 10.Think of 4. Multiply it by 5, then add 7. What number do you end with?
- 11.Magic trick! Think of 19. Double it, add 16, halve it, then take away 19. What number do you get?
- 12.I thought of a number, added 2 and then doubled it. I got 36. What was my number?
- 13.I thought of a number, added 7 and then doubled it. I got 20. What was my number?
- 14.I thought of a number, multiplied it by 2 and added 1. I got 5. What was my number?
- 15.I thought of a number, added 9 and then doubled it. I got 46. What was my number?
- 16.Think of 8. Multiply it by 4, then add 8. What number do you end with?
- 17.I thought of a number, multiplied it by 2 and added 1. I got 31. What was my number?
- 18.I thought of a number, added 8 and then doubled it. I got 30. What was my number?
- 19.I thought of a number, multiplied it by 5 and added 9. I got 44. What was my number?
- 20.I thought of a number, multiplied it by 4 and added 4. I got 20. What was my number?
- 21.Magic trick! Think of 15. Double it, add 10, halve it, then take away 15. What number do you get?
- 22.Magic trick! Think of 10. Double it, add 8, halve it, then take away 10. What number do you get?
- 23.I thought of a number, multiplied it by 5 and added 2. I got 77. What was my number?
- 24.Think of 11. Multiply it by 4, then add 4. What number do you end with?
- 25.Think of 14. Multiply it by 4, then add 3. What number do you end with?
- 26.Magic trick! Think of 11. Double it, add 6, halve it, then take away 11. What number do you get?
- 27.I thought of a number, added 9 and then doubled it. I got 56. What was my number?
- 28.Magic trick! Think of 19. Double it, add 4, halve it, then take away 19. What number do you get?
- 29.Magic trick! Think of 18. Double it, add 12, halve it, then take away 18. What number do you get?
- 30.I thought of a number, multiplied it by 5 and added 8. I got 63. What was my number?
- 31.I thought of a number, added 6 and then doubled it. I got 44. What was my number?
- 32.I thought of a number, multiplied it by 4 and added 4. I got 16. What was my number?
- 33.Magic trick! Think of 9. Double it, add 4, halve it, then take away 9. What number do you get?
- 34.I thought of a number, multiplied it by 3 and added 4. I got 49. What was my number?
- 35.I thought of a number, added 4 and then doubled it. I got 48. What was my number?
- 36.I thought of a number, added 8 and then doubled it. I got 46. What was my number?
- 37.Magic trick! Think of 20. Double it, add 18, halve it, then take away 20. What number do you get?
- 38.Magic trick! Think of 12. Double it, add 10, halve it, then take away 12. What number do you get?
- 39.I thought of a number, added 1 and then doubled it. I got 14. What was my number?
- 40.I thought of a number, multiplied it by 3 and added 1. I got 31. What was my number?
Answer key
- 16
- 32
- 35
- 7
- 4
- 15
- 3
- 11
- 47
- 27
- 8
- 16
- 3
- 2
- 14
- 40
- 15
- 7
- 7
- 4
- 5
- 4
- 15
- 48
- 59
- 3
- 19
- 2
- 6
- 11
- 16
- 3
- 2
- 15
- 20
- 15
- 9
- 5
- 6
- 10
Free maths tricks lessons, practice and worksheets at talentjr.in/maths-tricks