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 46. What was my number?
- 2.Think of 11. Multiply it by 3, then add 9. What number do you end with?
- 3.I thought of a number, multiplied it by 4 and added 6. I got 18. What was my number?
- 4.Magic trick! Think of 12. Double it, add 18, halve it, then take away 12. What number do you get?
- 5.Magic trick! Think of 4. Double it, add 12, halve it, then take away 4. What number do you get?
- 6.I thought of a number, added 7 and then doubled it. I got 32. What was my number?
- 7.Magic trick! Think of 16. Double it, add 4, halve it, then take away 16. What number do you get?
- 8.Think of 13. Multiply it by 5, then add 3. What number do you end with?
- 9.Think of 2. Multiply it by 3, then add 3. What number do you end with?
- 10.I thought of a number, multiplied it by 4 and added 3. I got 15. What was my number?
- 11.I thought of a number, added 6 and then doubled it. I got 34. What was my number?
- 12.Magic trick! Think of 13. Double it, add 12, halve it, then take away 13. What number do you get?
- 13.I thought of a number, added 5 and then doubled it. I got 30. What was my number?
- 14.Think of 3. Multiply it by 2, then add 6. What number do you end with?
- 15.Think of 12. Multiply it by 2, then add 8. What number do you end with?
- 16.I thought of a number, multiplied it by 2 and added 2. I got 14. What was my number?
- 17.Think of 13. Multiply it by 5, then add 7. What number do you end with?
- 18.Think of 13. Multiply it by 3, then add 6. What number do you end with?
- 19.Think of 5. Multiply it by 5, then add 6. What number do you end with?
- 20.Think of 10. Multiply it by 2, then add 1. What number do you end with?
- 21.Think of 13. Multiply it by 4, then add 4. What number do you end with?
- 22.Think of 7. Multiply it by 5, then add 8. What number do you end with?
- 23.I thought of a number, multiplied it by 2 and added 3. I got 19. What was my number?
- 24.Think of 9. Multiply it by 5, then add 4. What number do you end with?
- 25.Magic trick! Think of 12. Double it, add 12, halve it, then take away 12. What number do you get?
- 26.I thought of a number, added 8 and then doubled it. I got 42. What was my number?
- 27.Magic trick! Think of 18. Double it, add 18, halve it, then take away 18. What number do you get?
- 28.I thought of a number, added 5 and then doubled it. I got 26. What was my number?
- 29.Think of 7. Multiply it by 2, then add 4. What number do you end with?
- 30.Think of 12. Multiply it by 3, then add 9. What number do you end with?
- 31.I thought of a number, added 6 and then doubled it. I got 38. What was my number?
- 32.Magic trick! Think of 20. Double it, add 4, halve it, then take away 20. What number do you get?
- 33.Magic trick! Think of 14. Double it, add 14, halve it, then take away 14. What number do you get?
- 34.I thought of a number, multiplied it by 4 and added 5. I got 21. What was my number?
- 35.Magic trick! Think of 11. Double it, add 12, halve it, then take away 11. What number do you get?
- 36.Think of 13. Multiply it by 3, then add 5. What number do you end with?
- 37.Magic trick! Think of 11. Double it, add 18, halve it, then take away 11. What number do you get?
- 38.I thought of a number, added 5 and then doubled it. I got 44. What was my number?
- 39.Think of 11. Multiply it by 2, then add 6. What number do you end with?
- 40.Magic trick! Think of 18. Double it, add 16, halve it, then take away 18. What number do you get?
Answer key
- 20
- 42
- 3
- 9
- 6
- 9
- 2
- 68
- 9
- 3
- 11
- 6
- 10
- 12
- 32
- 6
- 72
- 45
- 31
- 21
- 56
- 43
- 8
- 49
- 6
- 13
- 9
- 8
- 18
- 45
- 13
- 2
- 7
- 4
- 6
- 44
- 9
- 17
- 28
- 8
Free maths tricks lessons, practice and worksheets at talentjr.in/maths-tricks