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 3 and then doubled it. I got 38. What was my number?
- 2.Magic trick! Think of 4. Double it, add 18, halve it, then take away 4. What number do you get?
- 3.I thought of a number, multiplied it by 3 and added 3. I got 9. What was my number?
- 4.I thought of a number, multiplied it by 2 and added 2. I got 16. What was my number?
- 5.I thought of a number, multiplied it by 2 and added 1. I got 11. What was my number?
- 6.I thought of a number, added 3 and then doubled it. I got 18. What was my number?
- 7.I thought of a number, multiplied it by 3 and added 2. I got 44. What was my number?
- 8.Magic trick! Think of 7. Double it, add 4, halve it, then take away 7. What number do you get?
- 9.Magic trick! Think of 6. Double it, add 14, halve it, then take away 6. What number do you get?
- 10.I thought of a number, added 1 and then doubled it. I got 14. What was my number?
- 11.Think of 7. Multiply it by 2, then add 6. What number do you end with?
- 12.I thought of a number, added 7 and then doubled it. I got 30. What was my number?
- 13.Magic trick! Think of 19. Double it, add 4, halve it, then take away 19. What number do you get?
- 14.Magic trick! Think of 20. Double it, add 12, halve it, then take away 20. What number do you get?
- 15.Magic trick! Think of 18. Double it, add 12, halve it, then take away 18. What number do you get?
- 16.Magic trick! Think of 4. Double it, add 12, halve it, then take away 4. What number do you get?
- 17.Magic trick! Think of 13. Double it, add 4, halve it, then take away 13. What number do you get?
- 18.I thought of a number, added 1 and then doubled it. I got 40. What was my number?
- 19.I thought of a number, multiplied it by 4 and added 1. I got 13. What was my number?
- 20.I thought of a number, multiplied it by 5 and added 7. I got 42. What was my number?
- 21.Think of 2. Multiply it by 5, then add 7. What number do you end with?
- 22.I thought of a number, multiplied it by 5 and added 8. I got 18. What was my number?
- 23.I thought of a number, added 5 and then doubled it. I got 38. What was my number?
- 24.Magic trick! Think of 19. Double it, add 10, halve it, then take away 19. What number do you get?
- 25.I thought of a number, added 2 and then doubled it. I got 36. What was my number?
- 26.Think of 3. Multiply it by 3, then add 8. What number do you end with?
- 27.I thought of a number, multiplied it by 3 and added 1. I got 19. What was my number?
- 28.Think of 2. Multiply it by 4, then add 9. What number do you end with?
- 29.I thought of a number, added 3 and then doubled it. I got 30. What was my number?
- 30.I thought of a number, multiplied it by 5 and added 6. I got 16. What was my number?
- 31.I thought of a number, added 3 and then doubled it. I got 24. What was my number?
- 32.I thought of a number, added 2 and then doubled it. I got 14. What was my number?
- 33.Think of 10. Multiply it by 2, then add 8. What number do you end with?
- 34.I thought of a number, added 1 and then doubled it. I got 38. What was my number?
- 35.I thought of a number, multiplied it by 4 and added 2. I got 54. What was my number?
- 36.I thought of a number, added 5 and then doubled it. I got 42. What was my number?
- 37.Think of 5. Multiply it by 3, then add 6. What number do you end with?
- 38.I thought of a number, multiplied it by 2 and added 9. I got 23. What was my number?
- 39.Think of 6. Multiply it by 5, then add 3. What number do you end with?
- 40.I thought of a number, multiplied it by 3 and added 5. I got 44. What was my number?
Answer key
- 16
- 9
- 2
- 7
- 5
- 6
- 14
- 2
- 7
- 6
- 20
- 8
- 2
- 6
- 6
- 6
- 2
- 19
- 3
- 7
- 17
- 2
- 14
- 5
- 16
- 17
- 6
- 17
- 12
- 2
- 9
- 5
- 28
- 18
- 13
- 16
- 21
- 7
- 33
- 13
Free maths tricks lessons, practice and worksheets at talentjr.in/maths-tricks