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.Think of 14. Multiply it by 4, then add 9. What number do you end with?
- 2.Think of 12. Multiply it by 2, then add 3. What number do you end with?
- 3.I thought of a number, multiplied it by 4 and added 5. I got 21. What was my number?
- 4.I thought of a number, multiplied it by 3 and added 5. I got 14. What was my number?
- 5.I thought of a number, multiplied it by 5 and added 1. I got 31. What was my number?
- 6.I thought of a number, multiplied it by 4 and added 9. I got 53. What was my number?
- 7.I thought of a number, added 7 and then doubled it. I got 34. What was my number?
- 8.Magic trick! Think of 4. Double it, add 4, halve it, then take away 4. What number do you get?
- 9.I thought of a number, added 8 and then doubled it. I got 38. What was my number?
- 10.Think of 14. Multiply it by 2, then add 4. What number do you end with?
- 11.Think of 9. Multiply it by 2, then add 8. What number do you end with?
- 12.Magic trick! Think of 4. Double it, add 12, halve it, then take away 4. What number do you get?
- 13.I thought of a number, multiplied it by 2 and added 2. I got 8. What was my number?
- 14.Magic trick! Think of 20. Double it, add 12, halve it, then take away 20. What number do you get?
- 15.Magic trick! Think of 15. Double it, add 12, halve it, then take away 15. What number do you get?
- 16.Think of 14. Multiply it by 2, then add 9. What number do you end with?
- 17.I thought of a number, multiplied it by 2 and added 2. I got 16. What was my number?
- 18.Magic trick! Think of 3. Double it, add 12, halve it, then take away 3. What number do you get?
- 19.Think of 9. Multiply it by 5, then add 4. What number do you end with?
- 20.I thought of a number, multiplied it by 2 and added 5. I got 35. What was my number?
- 21.Magic trick! Think of 9. Double it, add 10, halve it, then take away 9. What number do you get?
- 22.I thought of a number, added 9 and then doubled it. I got 42. What was my number?
- 23.Think of 8. Multiply it by 5, then add 4. What number do you end with?
- 24.I thought of a number, added 3 and then doubled it. I got 14. What was my number?
- 25.I thought of a number, multiplied it by 5 and added 1. I got 11. What was my number?
- 26.Think of 15. Multiply it by 2, then add 5. What number do you end with?
- 27.I thought of a number, multiplied it by 2 and added 4. I got 20. What was my number?
- 28.Magic trick! Think of 8. Double it, add 10, halve it, then take away 8. What number do you get?
- 29.Magic trick! Think of 14. Double it, add 18, halve it, then take away 14. What number do you get?
- 30.Think of 3. Multiply it by 4, then add 4. What number do you end with?
- 31.I thought of a number, multiplied it by 2 and added 5. I got 27. What was my number?
- 32.Think of 7. Multiply it by 5, then add 3. What number do you end with?
- 33.I thought of a number, multiplied it by 4 and added 8. I got 56. What was my number?
- 34.I thought of a number, added 6 and then doubled it. I got 28. What was my number?
- 35.Think of 9. Multiply it by 4, then add 6. What number do you end with?
- 36.I thought of a number, added 4 and then doubled it. I got 16. What was my number?
- 37.Magic trick! Think of 12. Double it, add 16, halve it, then take away 12. What number do you get?
- 38.Magic trick! Think of 19. Double it, add 14, halve it, then take away 19. What number do you get?
- 39.I thought of a number, multiplied it by 5 and added 6. I got 26. What was my number?
- 40.Magic trick! Think of 17. Double it, add 16, halve it, then take away 17. What number do you get?
Answer key
- 65
- 27
- 4
- 3
- 6
- 11
- 10
- 2
- 11
- 32
- 26
- 6
- 3
- 6
- 6
- 37
- 7
- 6
- 49
- 15
- 5
- 12
- 44
- 4
- 2
- 35
- 8
- 5
- 9
- 16
- 11
- 38
- 12
- 8
- 42
- 4
- 8
- 7
- 4
- 8
Free maths tricks lessons, practice and worksheets at talentjr.in/maths-tricks