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.Magic trick! Think of 15. Double it, add 6, halve it, then take away 15. What number do you get?
- 2.I thought of a number, multiplied it by 2 and added 4. I got 14. What was my number?
- 3.Think of 2. Multiply it by 2, then add 3. What number do you end with?
- 4.Think of 10. Multiply it by 5, then add 4. What number do you end with?
- 5.Think of 15. Multiply it by 5, then add 3. What number do you end with?
- 6.Magic trick! Think of 15. Double it, add 18, halve it, then take away 15. What number do you get?
- 7.I thought of a number, multiplied it by 3 and added 6. I got 39. What was my number?
- 8.Magic trick! Think of 10. Double it, add 18, halve it, then take away 10. What number do you get?
- 9.I thought of a number, multiplied it by 2 and added 2. I got 16. What was my number?
- 10.Magic trick! Think of 3. Double it, add 4, halve it, then take away 3. What number do you get?
- 11.Think of 8. Multiply it by 3, then add 5. What number do you end with?
- 12.I thought of a number, multiplied it by 2 and added 7. I got 15. What was my number?
- 13.I thought of a number, added 7 and then doubled it. I got 34. What was my number?
- 14.Think of 2. Multiply it by 4, then add 1. What number do you end with?
- 15.I thought of a number, added 7 and then doubled it. I got 30. What was my number?
- 16.I thought of a number, added 3 and then doubled it. I got 20. What was my number?
- 17.Think of 12. Multiply it by 2, then add 8. What number do you end with?
- 18.Think of 10. Multiply it by 2, then add 5. What number do you end with?
- 19.Magic trick! Think of 9. Double it, add 14, halve it, then take away 9. What number do you get?
- 20.Magic trick! Think of 3. Double it, add 14, halve it, then take away 3. What number do you get?
- 21.Magic trick! Think of 19. Double it, add 8, halve it, then take away 19. What number do you get?
- 22.Think of 8. Multiply it by 2, then add 5. What number do you end with?
- 23.Magic trick! Think of 16. Double it, add 14, halve it, then take away 16. What number do you get?
- 24.Think of 5. Multiply it by 5, then add 6. What number do you end with?
- 25.Think of 9. Multiply it by 3, then add 4. What number do you end with?
- 26.Magic trick! Think of 7. Double it, add 14, halve it, then take away 7. What number do you get?
- 27.Magic trick! Think of 5. Double it, add 14, halve it, then take away 5. What number do you get?
- 28.I thought of a number, multiplied it by 2 and added 3. I got 15. What was my number?
- 29.I thought of a number, multiplied it by 4 and added 2. I got 50. What was my number?
- 30.Magic trick! Think of 17. Double it, add 4, halve it, then take away 17. What number do you get?
- 31.I thought of a number, multiplied it by 5 and added 7. I got 67. What was my number?
- 32.Think of 10. Multiply it by 3, then add 5. What number do you end with?
- 33.Think of 7. Multiply it by 4, then add 4. What number do you end with?
- 34.Magic trick! Think of 5. Double it, add 6, halve it, then take away 5. What number do you get?
- 35.I thought of a number, added 6 and then doubled it. I got 48. What was my number?
- 36.Magic trick! Think of 4. Double it, add 6, halve it, then take away 4. What number do you get?
- 37.Think of 3. Multiply it by 3, then add 3. What number do you end with?
- 38.I thought of a number, multiplied it by 3 and added 7. I got 13. What was my number?
- 39.I thought of a number, added 3 and then doubled it. I got 28. What was my number?
- 40.I thought of a number, multiplied it by 3 and added 9. I got 21. What was my number?
Answer key
- 3
- 5
- 7
- 54
- 78
- 9
- 11
- 9
- 7
- 2
- 29
- 4
- 10
- 9
- 8
- 7
- 32
- 25
- 7
- 7
- 4
- 21
- 7
- 31
- 31
- 7
- 7
- 6
- 12
- 2
- 12
- 35
- 32
- 3
- 18
- 3
- 12
- 2
- 11
- 4
Free maths tricks lessons, practice and worksheets at talentjr.in/maths-tricks