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 2 and added 9. I got 21. What was my number?
- 2.I thought of a number, added 9 and then doubled it. I got 26. What was my number?
- 3.Magic trick! Think of 5. Double it, add 6, halve it, then take away 5. What number do you get?
- 4.I thought of a number, added 3 and then doubled it. I got 14. What was my number?
- 5.I thought of a number, multiplied it by 4 and added 2. I got 10. What was my number?
- 6.I thought of a number, added 2 and then doubled it. I got 26. What was my number?
- 7.Think of 3. Multiply it by 4, then add 8. What number do you end with?
- 8.I thought of a number, added 6 and then doubled it. I got 46. What was my number?
- 9.I thought of a number, multiplied it by 2 and added 7. I got 11. What was my number?
- 10.I thought of a number, multiplied it by 2 and added 2. I got 10. What was my number?
- 11.Magic trick! Think of 13. Double it, add 4, halve it, then take away 13. What number do you get?
- 12.I thought of a number, multiplied it by 4 and added 1. I got 13. What was my number?
- 13.Magic trick! Think of 18. Double it, add 12, halve it, then take away 18. What number do you get?
- 14.I thought of a number, multiplied it by 3 and added 7. I got 34. What was my number?
- 15.I thought of a number, multiplied it by 2 and added 5. I got 27. What was my number?
- 16.I thought of a number, multiplied it by 2 and added 2. I got 22. What was my number?
- 17.I thought of a number, multiplied it by 2 and added 6. I got 14. What was my number?
- 18.I thought of a number, multiplied it by 2 and added 1. I got 19. What was my number?
- 19.I thought of a number, added 9 and then doubled it. I got 40. What was my number?
- 20.Think of 14. Multiply it by 5, then add 2. What number do you end with?
- 21.I thought of a number, added 6 and then doubled it. I got 18. What was my number?
- 22.Think of 5. Multiply it by 3, then add 3. What number do you end with?
- 23.Think of 9. Multiply it by 2, then add 1. What number do you end with?
- 24.I thought of a number, added 9 and then doubled it. I got 56. What was my number?
- 25.Magic trick! Think of 9. Double it, add 12, halve it, then take away 9. What number do you get?
- 26.I thought of a number, multiplied it by 2 and added 5. I got 25. What was my number?
- 27.I thought of a number, multiplied it by 2 and added 2. I got 6. What was my number?
- 28.I thought of a number, added 3 and then doubled it. I got 16. What was my number?
- 29.Think of 2. Multiply it by 2, then add 2. What number do you end with?
- 30.Think of 13. Multiply it by 5, then add 4. What number do you end with?
- 31.Think of 4. Multiply it by 5, then add 6. What number do you end with?
- 32.I thought of a number, multiplied it by 2 and added 7. I got 37. What was my number?
- 33.Magic trick! Think of 14. Double it, add 18, halve it, then take away 14. What number do you get?
- 34.Magic trick! Think of 10. Double it, add 8, halve it, then take away 10. What number do you get?
- 35.Magic trick! Think of 5. Double it, add 14, halve it, then take away 5. What number do you get?
- 36.Think of 9. Multiply it by 3, then add 9. What number do you end with?
- 37.Think of 7. Multiply it by 2, then add 2. What number do you end with?
- 38.Magic trick! Think of 10. Double it, add 14, halve it, then take away 10. What number do you get?
- 39.Magic trick! Think of 5. Double it, add 12, halve it, then take away 5. What number do you get?
- 40.Magic trick! Think of 5. Double it, add 4, halve it, then take away 5. What number do you get?
Answer key
- 6
- 4
- 3
- 4
- 2
- 11
- 20
- 17
- 2
- 4
- 2
- 3
- 6
- 9
- 11
- 10
- 4
- 9
- 11
- 72
- 3
- 18
- 19
- 19
- 6
- 10
- 2
- 5
- 6
- 69
- 26
- 15
- 9
- 4
- 7
- 36
- 16
- 7
- 6
- 2
Free maths tricks lessons, practice and worksheets at talentjr.in/maths-tricks