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.Magic trick! Think of 11. Double it, add 16, halve it, then take away 11. What number do you get?
- 2.I thought of a number, added 8 and then doubled it. I got 32. What was my number?
- 3.I thought of a number, multiplied it by 3 and added 8. I got 14. What was my number?
- 4.Magic trick! Think of 3. Double it, add 12, halve it, then take away 3. What number do you get?
- 5.I thought of a number, added 7 and then doubled it. I got 44. What was my number?
- 6.Magic trick! Think of 7. Double it, add 4, halve it, then take away 7. What number do you get?
- 7.Think of 7. Multiply it by 2, then add 8. What number do you end with?
- 8.Think of 15. Multiply it by 2, then add 2. What number do you end with?
- 9.I thought of a number, added 1 and then doubled it. I got 26. What was my number?
- 10.Think of 13. Multiply it by 3, then add 4. What number do you end with?
- 11.Magic trick! Think of 19. Double it, add 10, halve it, then take away 19. What number do you get?
- 12.Magic trick! Think of 18. Double it, add 14, halve it, then take away 18. What number do you get?
- 13.I thought of a number, added 8 and then doubled it. I got 44. What was my number?
- 14.Think of 8. Multiply it by 5, then add 3. What number do you end with?
- 15.Magic trick! Think of 4. Double it, add 14, halve it, then take away 4. What number do you get?
- 16.I thought of a number, added 9 and then doubled it. I got 32. What was my number?
- 17.I thought of a number, added 3 and then doubled it. I got 34. What was my number?
- 18.Magic trick! Think of 18. Double it, add 4, halve it, then take away 18. What number do you get?
- 19.I thought of a number, added 9 and then doubled it. I got 30. What was my number?
- 20.Magic trick! Think of 5. Double it, add 16, halve it, then take away 5. What number do you get?
- 21.I thought of a number, multiplied it by 2 and added 3. I got 13. What was my number?
- 22.I thought of a number, added 1 and then doubled it. I got 28. What was my number?
- 23.I thought of a number, multiplied it by 2 and added 7. I got 13. What was my number?
- 24.I thought of a number, multiplied it by 5 and added 9. I got 79. What was my number?
- 25.Think of 7. Multiply it by 2, then add 9. What number do you end with?
- 26.Think of 9. Multiply it by 5, then add 8. What number do you end with?
- 27.I thought of a number, multiplied it by 3 and added 9. I got 30. What was my number?
- 28.Magic trick! Think of 3. Double it, add 10, halve it, then take away 3. What number do you get?
- 29.I thought of a number, added 1 and then doubled it. I got 22. What was my number?
- 30.Think of 10. Multiply it by 4, then add 2. What number do you end with?
- 31.I thought of a number, added 4 and then doubled it. I got 20. What was my number?
- 32.Magic trick! Think of 17. Double it, add 4, halve it, then take away 17. What number do you get?
- 33.I thought of a number, multiplied it by 3 and added 9. I got 18. What was my number?
- 34.I thought of a number, added 9 and then doubled it. I got 50. What was my number?
- 35.Magic trick! Think of 19. Double it, add 18, halve it, then take away 19. What number do you get?
- 36.Think of 12. Multiply it by 2, then add 8. What number do you end with?
- 37.I thought of a number, multiplied it by 3 and added 3. I got 9. What was my number?
- 38.I thought of a number, multiplied it by 5 and added 6. I got 16. What was my number?
- 39.Think of 13. Multiply it by 3, then add 9. What number do you end with?
- 40.I thought of a number, multiplied it by 5 and added 3. I got 13. What was my number?
Answer key
- 8
- 8
- 2
- 6
- 15
- 2
- 22
- 32
- 12
- 43
- 5
- 7
- 14
- 43
- 7
- 7
- 14
- 2
- 6
- 8
- 5
- 13
- 3
- 14
- 23
- 53
- 7
- 5
- 10
- 42
- 6
- 2
- 3
- 16
- 9
- 32
- 2
- 2
- 48
- 2
Free maths tricks lessons, practice and worksheets at talentjr.in/maths-tricks