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 22. What was my number?
- 2.Think of 3. Multiply it by 5, then add 5. What number do you end with?
- 3.I thought of a number, added 1 and then doubled it. I got 14. What was my number?
- 4.Think of 2. Multiply it by 2, then add 5. What number do you end with?
- 5.Magic trick! Think of 6. Double it, add 8, halve it, then take away 6. What number do you get?
- 6.Think of 7. Multiply it by 5, then add 6. What number do you end with?
- 7.Think of 7. Multiply it by 4, then add 6. What number do you end with?
- 8.I thought of a number, multiplied it by 5 and added 2. I got 42. What was my number?
- 9.Think of 13. Multiply it by 5, then add 7. What number do you end with?
- 10.I thought of a number, multiplied it by 3 and added 9. I got 39. What was my number?
- 11.Think of 5. Multiply it by 5, then add 3. What number do you end with?
- 12.Magic trick! Think of 15. Double it, add 16, halve it, then take away 15. What number do you get?
- 13.I thought of a number, multiplied it by 5 and added 5. I got 50. What was my number?
- 14.I thought of a number, multiplied it by 2 and added 3. I got 13. What was my number?
- 15.I thought of a number, multiplied it by 4 and added 8. I got 32. What was my number?
- 16.Think of 3. Multiply it by 3, then add 9. What number do you end with?
- 17.Magic trick! Think of 12. Double it, add 12, halve it, then take away 12. What number do you get?
- 18.I thought of a number, added 5 and then doubled it. I got 48. What was my number?
- 19.I thought of a number, multiplied it by 5 and added 5. I got 80. What was my number?
- 20.I thought of a number, multiplied it by 2 and added 5. I got 31. What was my number?
- 21.Magic trick! Think of 20. Double it, add 8, halve it, then take away 20. What number do you get?
- 22.Think of 14. Multiply it by 5, then add 4. What number do you end with?
- 23.I thought of a number, added 4 and then doubled it. I got 24. What was my number?
- 24.I thought of a number, added 3 and then doubled it. I got 28. What was my number?
- 25.I thought of a number, added 3 and then doubled it. I got 44. What was my number?
- 26.Magic trick! Think of 15. Double it, add 6, halve it, then take away 15. What number do you get?
- 27.Magic trick! Think of 13. Double it, add 14, halve it, then take away 13. What number do you get?
- 28.I thought of a number, added 8 and then doubled it. I got 28. What was my number?
- 29.I thought of a number, multiplied it by 4 and added 7. I got 23. What was my number?
- 30.Magic trick! Think of 19. Double it, add 8, halve it, then take away 19. What number do you get?
- 31.I thought of a number, multiplied it by 4 and added 9. I got 65. What was my number?
- 32.I thought of a number, added 2 and then doubled it. I got 26. What was my number?
- 33.I thought of a number, multiplied it by 5 and added 7. I got 47. What was my number?
- 34.Magic trick! Think of 2. Double it, add 4, halve it, then take away 2. What number do you get?
- 35.Think of 10. Multiply it by 2, then add 8. What number do you end with?
- 36.Think of 2. Multiply it by 4, then add 9. What number do you end with?
- 37.I thought of a number, added 7 and then doubled it. I got 46. What was my number?
- 38.I thought of a number, multiplied it by 5 and added 5. I got 45. What was my number?
- 39.I thought of a number, added 1 and then doubled it. I got 28. What was my number?
- 40.Magic trick! Think of 15. Double it, add 12, halve it, then take away 15. What number do you get?
Answer key
- 4
- 20
- 6
- 9
- 4
- 41
- 34
- 8
- 72
- 10
- 28
- 8
- 9
- 5
- 6
- 18
- 6
- 19
- 15
- 13
- 4
- 74
- 8
- 11
- 19
- 3
- 7
- 6
- 4
- 4
- 14
- 11
- 8
- 2
- 28
- 17
- 16
- 8
- 13
- 6
Free maths tricks lessons, practice and worksheets at talentjr.in/maths-tricks