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 4 and then doubled it. I got 38. What was my number?
- 2.Magic trick! Think of 10. Double it, add 18, halve it, then take away 10. What number do you get?
- 3.I thought of a number, added 7 and then doubled it. I got 20. What was my number?
- 4.I thought of a number, multiplied it by 4 and added 8. I got 56. What was my number?
- 5.Magic trick! Think of 16. Double it, add 10, halve it, then take away 16. What number do you get?
- 6.Think of 3. Multiply it by 5, then add 9. What number do you end with?
- 7.Magic trick! Think of 4. Double it, add 4, halve it, then take away 4. What number do you get?
- 8.I thought of a number, multiplied it by 3 and added 3. I got 45. What was my number?
- 9.Think of 15. Multiply it by 5, then add 7. What number do you end with?
- 10.Think of 4. Multiply it by 3, then add 1. What number do you end with?
- 11.I thought of a number, added 3 and then doubled it. I got 42. What was my number?
- 12.I thought of a number, multiplied it by 3 and added 8. I got 47. What was my number?
- 13.I thought of a number, multiplied it by 4 and added 4. I got 36. What was my number?
- 14.I thought of a number, added 2 and then doubled it. I got 40. What was my number?
- 15.Think of 12. Multiply it by 3, then add 8. What number do you end with?
- 16.I thought of a number, multiplied it by 5 and added 5. I got 55. What was my number?
- 17.Magic trick! Think of 5. Double it, add 4, halve it, then take away 5. What number do you get?
- 18.Think of 10. Multiply it by 3, then add 6. What number do you end with?
- 19.Think of 3. Multiply it by 4, then add 2. What number do you end with?
- 20.I thought of a number, multiplied it by 3 and added 5. I got 14. What was my number?
- 21.I thought of a number, added 4 and then doubled it. I got 32. What was my number?
- 22.Magic trick! Think of 11. Double it, add 8, halve it, then take away 11. What number do you get?
- 23.Think of 7. Multiply it by 3, then add 5. What number do you end with?
- 24.I thought of a number, multiplied it by 2 and added 9. I got 13. What was my number?
- 25.Think of 15. Multiply it by 4, then add 2. What number do you end with?
- 26.Think of 11. Multiply it by 3, then add 4. What number do you end with?
- 27.Think of 12. Multiply it by 4, then add 1. What number do you end with?
- 28.Think of 4. Multiply it by 2, then add 6. What number do you end with?
- 29.Think of 10. Multiply it by 4, then add 5. What number do you end with?
- 30.I thought of a number, added 4 and then doubled it. I got 34. What was my number?
- 31.I thought of a number, added 1 and then doubled it. I got 18. What was my number?
- 32.Think of 7. Multiply it by 2, then add 2. What number do you end with?
- 33.I thought of a number, added 9 and then doubled it. I got 48. What was my number?
- 34.Magic trick! Think of 18. Double it, add 10, halve it, then take away 18. What number do you get?
- 35.I thought of a number, added 1 and then doubled it. I got 24. What was my number?
- 36.Magic trick! Think of 15. Double it, add 10, halve it, then take away 15. What number do you get?
- 37.Think of 6. Multiply it by 4, then add 4. What number do you end with?
- 38.I thought of a number, added 1 and then doubled it. I got 32. What was my number?
- 39.Magic trick! Think of 8. Double it, add 4, halve it, then take away 8. What number do you get?
- 40.Think of 11. Multiply it by 4, then add 2. What number do you end with?
Answer key
- 15
- 9
- 3
- 12
- 5
- 24
- 2
- 14
- 82
- 13
- 18
- 13
- 8
- 18
- 44
- 10
- 2
- 36
- 14
- 3
- 12
- 4
- 26
- 2
- 62
- 37
- 49
- 14
- 45
- 13
- 8
- 16
- 15
- 5
- 11
- 5
- 28
- 15
- 2
- 46
Free maths tricks lessons, practice and worksheets at talentjr.in/maths-tricks