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, multiplied it by 3 and added 3. I got 42. What was my number?
- 2.Magic trick! Think of 13. Double it, add 8, halve it, then take away 13. What number do you get?
- 3.Think of 9. Multiply it by 4, then add 5. What number do you end with?
- 4.Think of 8. Multiply it by 4, then add 8. What number do you end with?
- 5.Think of 4. Multiply it by 2, then add 9. What number do you end with?
- 6.Magic trick! Think of 20. Double it, add 14, halve it, then take away 20. What number do you get?
- 7.I thought of a number, multiplied it by 5 and added 8. I got 18. What was my number?
- 8.Think of 9. Multiply it by 4, then add 2. What number do you end with?
- 9.Think of 9. Multiply it by 3, then add 7. What number do you end with?
- 10.I thought of a number, added 1 and then doubled it. I got 16. What was my number?
- 11.Think of 5. Multiply it by 2, then add 2. What number do you end with?
- 12.I thought of a number, added 9 and then doubled it. I got 54. What was my number?
- 13.I thought of a number, multiplied it by 2 and added 9. I got 17. What was my number?
- 14.Think of 4. Multiply it by 2, then add 2. What number do you end with?
- 15.Think of 14. Multiply it by 3, then add 8. What number do you end with?
- 16.I thought of a number, added 7 and then doubled it. I got 46. What was my number?
- 17.I thought of a number, added 2 and then doubled it. I got 32. What was my number?
- 18.Magic trick! Think of 11. Double it, add 8, halve it, then take away 11. What number do you get?
- 19.I thought of a number, added 5 and then doubled it. I got 44. What was my number?
- 20.Magic trick! Think of 19. Double it, add 14, halve it, then take away 19. What number do you get?
- 21.I thought of a number, added 6 and then doubled it. I got 28. What was my number?
- 22.I thought of a number, added 9 and then doubled it. I got 48. What was my number?
- 23.I thought of a number, added 4 and then doubled it. I got 20. What was my number?
- 24.Think of 11. Multiply it by 2, then add 9. What number do you end with?
- 25.I thought of a number, added 2 and then doubled it. I got 26. What was my number?
- 26.Think of 9. Multiply it by 5, then add 2. What number do you end with?
- 27.I thought of a number, added 7 and then doubled it. I got 24. What was my number?
- 28.Magic trick! Think of 3. Double it, add 8, halve it, then take away 3. What number do you get?
- 29.I thought of a number, added 2 and then doubled it. I got 16. What was my number?
- 30.I thought of a number, added 1 and then doubled it. I got 34. What was my number?
- 31.I thought of a number, added 3 and then doubled it. I got 18. What was my number?
- 32.Think of 4. Multiply it by 5, then add 1. What number do you end with?
- 33.Magic trick! Think of 12. Double it, add 14, halve it, then take away 12. What number do you get?
- 34.Think of 4. Multiply it by 3, then add 5. What number do you end with?
- 35.I thought of a number, added 6 and then doubled it. I got 40. What was my number?
- 36.Magic trick! Think of 16. Double it, add 8, halve it, then take away 16. What number do you get?
- 37.Magic trick! Think of 2. Double it, add 10, halve it, then take away 2. What number do you get?
- 38.Think of 4. Multiply it by 5, then add 2. What number do you end with?
- 39.I thought of a number, multiplied it by 2 and added 6. I got 22. What was my number?
- 40.Think of 14. Multiply it by 3, then add 4. What number do you end with?
Answer key
- 13
- 4
- 41
- 40
- 17
- 7
- 2
- 38
- 34
- 7
- 12
- 18
- 4
- 10
- 50
- 16
- 14
- 4
- 17
- 7
- 8
- 15
- 6
- 31
- 11
- 47
- 5
- 4
- 6
- 16
- 6
- 21
- 7
- 17
- 14
- 4
- 5
- 22
- 8
- 46
Free maths tricks lessons, practice and worksheets at talentjr.in/maths-tricks