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 1 and then doubled it. I got 36. What was my number?
- 2.I thought of a number, multiplied it by 4 and added 1. I got 9. What was my number?
- 3.I thought of a number, multiplied it by 5 and added 3. I got 23. What was my number?
- 4.Think of 2. Multiply it by 3, then add 9. What number do you end with?
- 5.I thought of a number, added 8 and then doubled it. I got 22. What was my number?
- 6.I thought of a number, multiplied it by 4 and added 1. I got 29. What was my number?
- 7.I thought of a number, multiplied it by 5 and added 6. I got 46. What was my number?
- 8.I thought of a number, added 3 and then doubled it. I got 16. What was my number?
- 9.I thought of a number, multiplied it by 4 and added 8. I got 64. What was my number?
- 10.Think of 15. Multiply it by 4, then add 3. What number do you end with?
- 11.I thought of a number, multiplied it by 5 and added 9. I got 69. What was my number?
- 12.I thought of a number, multiplied it by 5 and added 1. I got 71. What was my number?
- 13.Magic trick! Think of 20. Double it, add 10, halve it, then take away 20. What number do you get?
- 14.Think of 10. Multiply it by 5, then add 7. What number do you end with?
- 15.I thought of a number, multiplied it by 4 and added 3. I got 11. What was my number?
- 16.Magic trick! Think of 16. Double it, add 10, halve it, then take away 16. What number do you get?
- 17.Think of 15. Multiply it by 4, then add 9. What number do you end with?
- 18.Think of 5. Multiply it by 5, then add 1. What number do you end with?
- 19.Think of 14. Multiply it by 4, then add 6. What number do you end with?
- 20.I thought of a number, added 9 and then doubled it. I got 30. What was my number?
- 21.I thought of a number, added 1 and then doubled it. I got 32. What was my number?
- 22.Think of 11. Multiply it by 2, then add 9. What number do you end with?
- 23.Magic trick! Think of 14. Double it, add 16, halve it, then take away 14. What number do you get?
- 24.Magic trick! Think of 17. Double it, add 18, halve it, then take away 17. What number do you get?
- 25.Magic trick! Think of 11. Double it, add 6, halve it, then take away 11. What number do you get?
- 26.Magic trick! Think of 13. Double it, add 14, halve it, then take away 13. What number do you get?
- 27.I thought of a number, multiplied it by 5 and added 2. I got 52. What was my number?
- 28.I thought of a number, multiplied it by 5 and added 5. I got 70. What was my number?
- 29.Think of 7. Multiply it by 3, then add 2. What number do you end with?
- 30.I thought of a number, added 6 and then doubled it. I got 28. What was my number?
- 31.I thought of a number, added 9 and then doubled it. I got 28. What was my number?
- 32.Think of 13. Multiply it by 3, then add 4. What number do you end with?
- 33.I thought of a number, multiplied it by 2 and added 7. I got 19. What was my number?
- 34.Think of 10. Multiply it by 5, then add 2. What number do you end with?
- 35.I thought of a number, multiplied it by 3 and added 5. I got 29. What was my number?
- 36.I thought of a number, multiplied it by 5 and added 4. I got 24. What was my number?
- 37.Think of 5. Multiply it by 2, then add 9. What number do you end with?
- 38.Magic trick! Think of 18. Double it, add 16, halve it, then take away 18. What number do you get?
- 39.I thought of a number, multiplied it by 2 and added 9. I got 37. What was my number?
- 40.I thought of a number, added 6 and then doubled it. I got 42. What was my number?
Answer key
- 17
- 2
- 4
- 15
- 3
- 7
- 8
- 5
- 14
- 63
- 12
- 14
- 5
- 57
- 2
- 5
- 69
- 26
- 62
- 6
- 15
- 31
- 8
- 9
- 3
- 7
- 10
- 13
- 23
- 8
- 5
- 43
- 6
- 52
- 8
- 4
- 19
- 8
- 14
- 15
Free maths tricks lessons, practice and worksheets at talentjr.in/maths-tricks