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 5 and then doubled it. I got 24. What was my number?
- 2.I thought of a number, multiplied it by 5 and added 3. I got 68. What was my number?
- 3.I thought of a number, added 5 and then doubled it. I got 36. What was my number?
- 4.I thought of a number, added 9 and then doubled it. I got 36. What was my number?
- 5.I thought of a number, multiplied it by 5 and added 1. I got 46. What was my number?
- 6.Think of 8. Multiply it by 2, then add 7. What number do you end with?
- 7.I thought of a number, added 7 and then doubled it. I got 48. What was my number?
- 8.Think of 4. Multiply it by 3, then add 7. What number do you end with?
- 9.Think of 3. Multiply it by 2, then add 5. What number do you end with?
- 10.Think of 4. Multiply it by 5, then add 5. What number do you end with?
- 11.Magic trick! Think of 8. Double it, add 10, halve it, then take away 8. What number do you get?
- 12.I thought of a number, added 8 and then doubled it. I got 26. What was my number?
- 13.Think of 3. Multiply it by 2, then add 4. What number do you end with?
- 14.I thought of a number, added 8 and then doubled it. I got 48. What was my number?
- 15.Think of 3. Multiply it by 4, then add 3. What number do you end with?
- 16.I thought of a number, added 4 and then doubled it. I got 46. What was my number?
- 17.I thought of a number, multiplied it by 3 and added 8. I got 53. What was my number?
- 18.I thought of a number, multiplied it by 3 and added 5. I got 29. What was my number?
- 19.Think of 2. Multiply it by 4, then add 3. What number do you end with?
- 20.I thought of a number, multiplied it by 5 and added 1. I got 31. What was my number?
- 21.Think of 3. Multiply it by 3, then add 9. What number do you end with?
- 22.I thought of a number, added 5 and then doubled it. I got 20. What was my number?
- 23.I thought of a number, multiplied it by 5 and added 3. I got 43. What was my number?
- 24.Magic trick! Think of 12. Double it, add 12, halve it, then take away 12. What number do you get?
- 25.Think of 14. Multiply it by 4, then add 9. What number do you end with?
- 26.I thought of a number, added 8 and then doubled it. I got 36. What was my number?
- 27.I thought of a number, added 8 and then doubled it. I got 42. What was my number?
- 28.I thought of a number, added 4 and then doubled it. I got 36. What was my number?
- 29.Magic trick! Think of 10. Double it, add 12, halve it, then take away 10. What number do you get?
- 30.Think of 11. Multiply it by 4, then add 8. What number do you end with?
- 31.Think of 14. Multiply it by 4, then add 5. What number do you end with?
- 32.Magic trick! Think of 12. Double it, add 4, halve it, then take away 12. What number do you get?
- 33.I thought of a number, added 3 and then doubled it. I got 26. What was my number?
- 34.Magic trick! Think of 3. Double it, add 16, halve it, then take away 3. What number do you get?
- 35.Magic trick! Think of 8. Double it, add 16, halve it, then take away 8. What number do you get?
- 36.Magic trick! Think of 3. Double it, add 10, halve it, then take away 3. What number do you get?
- 37.Magic trick! Think of 7. Double it, add 6, halve it, then take away 7. What number do you get?
- 38.I thought of a number, added 3 and then doubled it. I got 46. What was my number?
- 39.Magic trick! Think of 15. Double it, add 14, halve it, then take away 15. What number do you get?
- 40.Magic trick! Think of 15. Double it, add 6, halve it, then take away 15. What number do you get?
Answer key
- 7
- 13
- 13
- 9
- 9
- 23
- 17
- 19
- 11
- 25
- 5
- 5
- 10
- 16
- 15
- 19
- 15
- 8
- 11
- 6
- 18
- 5
- 8
- 6
- 65
- 10
- 13
- 14
- 6
- 52
- 61
- 2
- 10
- 8
- 8
- 5
- 3
- 20
- 7
- 3
Free maths tricks lessons, practice and worksheets at talentjr.in/maths-tricks