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 4 and added 2. I got 14. What was my number?
- 2.Think of 6. Multiply it by 3, then add 2. What number do you end with?
- 3.I thought of a number, multiplied it by 5 and added 6. I got 21. What was my number?
- 4.I thought of a number, added 9 and then doubled it. I got 56. What was my number?
- 5.I thought of a number, added 9 and then doubled it. I got 46. What was my number?
- 6.Think of 6. Multiply it by 2, then add 9. What number do you end with?
- 7.Magic trick! Think of 6. Double it, add 4, halve it, then take away 6. What number do you get?
- 8.Magic trick! Think of 8. Double it, add 6, halve it, then take away 8. What number do you get?
- 9.Magic trick! Think of 2. Double it, add 12, halve it, then take away 2. What number do you get?
- 10.I thought of a number, added 1 and then doubled it. I got 32. What was my number?
- 11.I thought of a number, added 8 and then doubled it. I got 32. What was my number?
- 12.Magic trick! Think of 9. Double it, add 6, halve it, then take away 9. What number do you get?
- 13.Think of 11. Multiply it by 2, then add 5. What number do you end with?
- 14.Magic trick! Think of 8. Double it, add 12, halve it, then take away 8. What number do you get?
- 15.Think of 4. Multiply it by 2, then add 3. What number do you end with?
- 16.I thought of a number, multiplied it by 4 and added 7. I got 51. What was my number?
- 17.Magic trick! Think of 20. Double it, add 8, halve it, then take away 20. What number do you get?
- 18.Magic trick! Think of 10. Double it, add 8, halve it, then take away 10. What number do you get?
- 19.Think of 5. Multiply it by 2, then add 7. What number do you end with?
- 20.I thought of a number, multiplied it by 2 and added 3. I got 9. What was my number?
- 21.Think of 12. Multiply it by 5, then add 1. What number do you end with?
- 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 9. I got 29. What was my number?
- 24.Magic trick! Think of 19. Double it, add 14, halve it, then take away 19. What number do you get?
- 25.I thought of a number, added 5 and then doubled it. I got 46. What was my number?
- 26.I thought of a number, added 5 and then doubled it. I got 40. What was my number?
- 27.Magic trick! Think of 20. Double it, add 14, halve it, then take away 20. What number do you get?
- 28.Magic trick! Think of 15. Double it, add 10, halve it, then take away 15. What number do you get?
- 29.Magic trick! Think of 8. Double it, add 4, halve it, then take away 8. What number do you get?
- 30.I thought of a number, added 1 and then doubled it. I got 38. What was my number?
- 31.Magic trick! Think of 5. Double it, add 18, halve it, then take away 5. What number do you get?
- 32.Think of 11. Multiply it by 3, then add 6. What number do you end with?
- 33.Magic trick! Think of 5. Double it, add 4, halve it, then take away 5. What number do you get?
- 34.Think of 3. Multiply it by 4, then add 8. What number do you end with?
- 35.Think of 8. Multiply it by 2, then add 1. What number do you end with?
- 36.Magic trick! Think of 17. Double it, add 18, halve it, then take away 17. What number do you get?
- 37.I thought of a number, multiplied it by 5 and added 6. I got 66. What was my number?
- 38.I thought of a number, multiplied it by 4 and added 5. I got 37. What was my number?
- 39.Think of 5. Multiply it by 3, then add 5. What number do you end with?
- 40.Magic trick! Think of 17. Double it, add 14, halve it, then take away 17. What number do you get?
Answer key
- 3
- 20
- 3
- 19
- 14
- 21
- 2
- 3
- 6
- 15
- 8
- 3
- 27
- 6
- 11
- 11
- 4
- 4
- 17
- 3
- 61
- 10
- 10
- 7
- 18
- 15
- 7
- 5
- 2
- 18
- 9
- 39
- 2
- 20
- 17
- 9
- 12
- 8
- 20
- 7
Free maths tricks lessons, practice and worksheets at talentjr.in/maths-tricks