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 19. Double it, add 16, halve it, then take away 19. What number do you get?
- 2.Think of 8. Multiply it by 2, then add 5. What number do you end with?
- 3.Magic trick! Think of 4. Double it, add 4, halve it, then take away 4. What number do you get?
- 4.I thought of a number, added 8 and then doubled it. I got 40. What was my number?
- 5.Magic trick! Think of 17. Double it, add 6, halve it, then take away 17. What number do you get?
- 6.Magic trick! Think of 12. Double it, add 18, halve it, then take away 12. What number do you get?
- 7.I thought of a number, added 1 and then doubled it. I got 16. What was my number?
- 8.I thought of a number, multiplied it by 4 and added 1. I got 9. What was my number?
- 9.I thought of a number, multiplied it by 2 and added 5. I got 15. What was my number?
- 10.I thought of a number, added 9 and then doubled it. I got 50. What was my number?
- 11.I thought of a number, added 2 and then doubled it. I got 24. What was my number?
- 12.Think of 5. Multiply it by 3, then add 6. What number do you end with?
- 13.Think of 5. Multiply it by 5, then add 4. What number do you end with?
- 14.I thought of a number, added 3 and then doubled it. I got 34. What was my number?
- 15.I thought of a number, added 3 and then doubled it. I got 18. What was my number?
- 16.I thought of a number, multiplied it by 5 and added 2. I got 72. What was my number?
- 17.Magic trick! Think of 14. Double it, add 14, halve it, then take away 14. What number do you get?
- 18.I thought of a number, multiplied it by 2 and added 4. I got 34. What was my number?
- 19.Magic trick! Think of 20. Double it, add 4, halve it, then take away 20. What number do you get?
- 20.I thought of a number, multiplied it by 4 and added 3. I got 23. What was my number?
- 21.Magic trick! Think of 19. Double it, add 10, halve it, then take away 19. What number do you get?
- 22.Think of 9. Multiply it by 5, then add 9. What number do you end with?
- 23.Magic trick! Think of 14. Double it, add 12, halve it, then take away 14. What number do you get?
- 24.Magic trick! Think of 2. Double it, add 16, halve it, then take away 2. What number do you get?
- 25.I thought of a number, multiplied it by 4 and added 6. I got 58. What was my number?
- 26.Magic trick! Think of 10. Double it, add 18, halve it, then take away 10. What number do you get?
- 27.Think of 7. Multiply it by 2, then add 5. What number do you end with?
- 28.Magic trick! Think of 4. Double it, add 14, halve it, then take away 4. What number do you get?
- 29.Think of 5. Multiply it by 5, then add 2. What number do you end with?
- 30.Think of 14. Multiply it by 2, then add 7. What number do you end with?
- 31.I thought of a number, added 4 and then doubled it. I got 20. What was my number?
- 32.Magic trick! Think of 5. Double it, add 10, halve it, then take away 5. What number do you get?
- 33.Think of 14. Multiply it by 3, then add 6. What number do you end with?
- 34.Think of 3. Multiply it by 5, then add 3. What number do you end with?
- 35.Magic trick! Think of 16. Double it, add 10, halve it, then take away 16. What number do you get?
- 36.I thought of a number, added 8 and then doubled it. I got 24. What was my number?
- 37.Think of 2. Multiply it by 5, then add 4. What number do you end with?
- 38.I thought of a number, multiplied it by 2 and added 2. I got 12. What was my number?
- 39.Think of 3. Multiply it by 2, then add 1. What number do you end with?
- 40.I thought of a number, added 4 and then doubled it. I got 22. What was my number?
Answer key
- 8
- 21
- 2
- 12
- 3
- 9
- 7
- 2
- 5
- 16
- 10
- 21
- 29
- 14
- 6
- 14
- 7
- 15
- 2
- 5
- 5
- 54
- 6
- 8
- 13
- 9
- 19
- 7
- 27
- 35
- 6
- 5
- 48
- 18
- 5
- 4
- 14
- 5
- 7
- 7
Free maths tricks lessons, practice and worksheets at talentjr.in/maths-tricks