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 8 and then doubled it. I got 30. What was my number?
- 2.Think of 10. Multiply it by 2, then add 6. What number do you end with?
- 3.Magic trick! Think of 14. Double it, add 16, halve it, then take away 14. What number do you get?
- 4.Think of 2. Multiply it by 4, then add 7. What number do you end with?
- 5.I thought of a number, multiplied it by 3 and added 3. I got 15. What was my number?
- 6.I thought of a number, added 4 and then doubled it. I got 28. What was my number?
- 7.Magic trick! Think of 19. Double it, add 18, halve it, then take away 19. What number do you get?
- 8.I thought of a number, multiplied it by 2 and added 5. I got 19. What was my number?
- 9.I thought of a number, added 4 and then doubled it. I got 38. What was my number?
- 10.Magic trick! Think of 6. Double it, add 6, halve it, then take away 6. What number do you get?
- 11.Magic trick! Think of 3. Double it, add 18, halve it, then take away 3. What number do you get?
- 12.I thought of a number, multiplied it by 5 and added 2. I got 42. What was my number?
- 13.Magic trick! Think of 7. Double it, add 8, halve it, then take away 7. What number do you get?
- 14.Think of 11. Multiply it by 3, then add 4. What number do you end with?
- 15.Magic trick! Think of 16. Double it, add 10, halve it, then take away 16. What number do you get?
- 16.Think of 7. Multiply it by 2, then add 3. What number do you end with?
- 17.I thought of a number, added 1 and then doubled it. I got 28. What was my number?
- 18.Think of 14. Multiply it by 2, then add 6. What number do you end with?
- 19.I thought of a number, added 3 and then doubled it. I got 46. What was my number?
- 20.Magic trick! Think of 12. Double it, add 18, halve it, then take away 12. What number do you get?
- 21.I thought of a number, multiplied it by 4 and added 9. I got 25. What was my number?
- 22.I thought of a number, multiplied it by 2 and added 4. I got 24. What was my number?
- 23.I thought of a number, multiplied it by 2 and added 3. I got 17. What was my number?
- 24.Think of 12. Multiply it by 5, then add 2. What number do you end with?
- 25.Think of 8. Multiply it by 4, then add 9. What number do you end with?
- 26.I thought of a number, added 9 and then doubled it. I got 42. What was my number?
- 27.Think of 3. Multiply it by 3, then add 9. What number do you end with?
- 28.I thought of a number, added 7 and then doubled it. I got 46. What was my number?
- 29.Think of 10. Multiply it by 3, then add 2. What number do you end with?
- 30.Magic trick! Think of 16. Double it, add 8, halve it, then take away 16. What number do you get?
- 31.Think of 9. Multiply it by 5, then add 7. What number do you end with?
- 32.Think of 14. Multiply it by 2, then add 4. What number do you end with?
- 33.Magic trick! Think of 15. Double it, add 18, halve it, then take away 15. What number do you get?
- 34.Think of 4. Multiply it by 4, then add 1. What number do you end with?
- 35.I thought of a number, added 8 and then doubled it. I got 40. What was my number?
- 36.I thought of a number, multiplied it by 3 and added 6. I got 15. What was my number?
- 37.I thought of a number, added 5 and then doubled it. I got 20. What was my number?
- 38.I thought of a number, added 9 and then doubled it. I got 48. What was my number?
- 39.I thought of a number, added 5 and then doubled it. I got 32. What was my number?
- 40.Think of 10. Multiply it by 3, then add 8. What number do you end with?
Answer key
- 7
- 26
- 8
- 15
- 4
- 10
- 9
- 7
- 15
- 3
- 9
- 8
- 4
- 37
- 5
- 17
- 13
- 34
- 20
- 9
- 4
- 10
- 7
- 62
- 41
- 12
- 18
- 16
- 32
- 4
- 52
- 32
- 9
- 17
- 12
- 3
- 5
- 15
- 11
- 38
Free maths tricks lessons, practice and worksheets at talentjr.in/maths-tricks