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 5 and then doubled it. I got 32. What was my number?
- 2.I thought of a number, multiplied it by 4 and added 9. I got 25. What was my number?
- 3.Think of 4. Multiply it by 5, then add 8. What number do you end with?
- 4.I thought of a number, added 1 and then doubled it. I got 10. What was my number?
- 5.I thought of a number, added 3 and then doubled it. I got 38. What was my number?
- 6.Magic trick! Think of 19. Double it, add 10, halve it, then take away 19. What number do you get?
- 7.I thought of a number, added 9 and then doubled it. I got 44. What was my number?
- 8.Magic trick! Think of 18. Double it, add 14, halve it, then take away 18. What number do you get?
- 9.Magic trick! Think of 9. Double it, add 16, halve it, then take away 9. What number do you get?
- 10.Magic trick! Think of 18. Double it, add 6, halve it, then take away 18. What number do you get?
- 11.I thought of a number, added 3 and then doubled it. I got 22. What was my number?
- 12.I thought of a number, multiplied it by 2 and added 1. I got 9. What was my number?
- 13.Magic trick! Think of 8. Double it, add 14, halve it, then take away 8. What number do you get?
- 14.Think of 5. Multiply it by 3, then add 9. What number do you end with?
- 15.Think of 8. Multiply it by 3, then add 3. What number do you end with?
- 16.I thought of a number, added 8 and then doubled it. I got 56. What was my number?
- 17.Think of 9. Multiply it by 2, then add 3. What number do you end with?
- 18.Think of 3. Multiply it by 3, then add 2. What number do you end with?
- 19.Think of 15. Multiply it by 4, then add 9. What number do you end with?
- 20.Magic trick! Think of 5. Double it, add 18, halve it, then take away 5. What number do you get?
- 21.Magic trick! Think of 7. Double it, add 18, halve it, then take away 7. What number do you get?
- 22.Magic trick! Think of 4. Double it, add 14, halve it, then take away 4. What number do you get?
- 23.Magic trick! Think of 2. Double it, add 10, halve it, then take away 2. What number do you get?
- 24.I thought of a number, multiplied it by 3 and added 8. I got 26. What was my number?
- 25.Magic trick! Think of 15. Double it, add 16, halve it, then take away 15. What number do you get?
- 26.I thought of a number, added 6 and then doubled it. I got 46. What was my number?
- 27.I thought of a number, multiplied it by 5 and added 2. I got 27. What was my number?
- 28.Think of 13. Multiply it by 4, then add 6. What number do you end with?
- 29.I thought of a number, multiplied it by 3 and added 3. I got 15. What was my number?
- 30.Think of 10. Multiply it by 3, then add 3. What number do you end with?
- 31.I thought of a number, multiplied it by 4 and added 6. I got 14. What was my number?
- 32.Magic trick! Think of 3. Double it, add 10, halve it, then take away 3. What number do you get?
- 33.Think of 7. Multiply it by 2, then add 4. What number do you end with?
- 34.I thought of a number, added 4 and then doubled it. I got 30. What was my number?
- 35.Think of 12. Multiply it by 4, then add 9. What number do you end with?
- 36.Think of 8. Multiply it by 3, then add 2. What number do you end with?
- 37.Magic trick! Think of 9. Double it, add 18, halve it, then take away 9. What number do you get?
- 38.I thought of a number, multiplied it by 3 and added 1. I got 13. What was my number?
- 39.Magic trick! Think of 16. Double it, add 16, halve it, then take away 16. What number do you get?
- 40.I thought of a number, multiplied it by 3 and added 5. I got 32. What was my number?
Answer key
- 11
- 4
- 28
- 4
- 16
- 5
- 13
- 7
- 8
- 3
- 8
- 4
- 7
- 24
- 27
- 20
- 21
- 11
- 69
- 9
- 9
- 7
- 5
- 6
- 8
- 17
- 5
- 58
- 4
- 33
- 2
- 5
- 18
- 11
- 57
- 26
- 9
- 4
- 8
- 9
Free maths tricks lessons, practice and worksheets at talentjr.in/maths-tricks