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 7. Double it, add 14, halve it, then take away 7. What number do you get?
- 2.I thought of a number, multiplied it by 3 and added 4. I got 19. What was my number?
- 3.Think of 13. Multiply it by 2, then add 3. What number do you end with?
- 4.I thought of a number, added 1 and then doubled it. I got 16. What was my number?
- 5.I thought of a number, multiplied it by 5 and added 3. I got 43. What was my number?
- 6.I thought of a number, added 4 and then doubled it. I got 48. What was my number?
- 7.Magic trick! Think of 3. Double it, add 8, halve it, then take away 3. What number do you get?
- 8.I thought of a number, added 6 and then doubled it. I got 28. What was my number?
- 9.Think of 6. Multiply it by 2, then add 1. What number do you end with?
- 10.Think of 4. Multiply it by 5, then add 3. What number do you end with?
- 11.Think of 5. Multiply it by 3, then add 5. What number do you end with?
- 12.Magic trick! Think of 8. Double it, add 6, halve it, then take away 8. What number do you get?
- 13.Magic trick! Think of 7. Double it, add 12, halve it, then take away 7. What number do you get?
- 14.Think of 7. Multiply it by 2, then add 7. What number do you end with?
- 15.Magic trick! Think of 18. Double it, add 8, halve it, then take away 18. What number do you get?
- 16.Think of 15. Multiply it by 2, then add 5. What number do you end with?
- 17.Think of 6. Multiply it by 3, then add 6. What number do you end with?
- 18.I thought of a number, added 8 and then doubled it. I got 36. What was my number?
- 19.Magic trick! Think of 20. Double it, add 18, halve it, then take away 20. What number do you get?
- 20.Magic trick! Think of 20. Double it, add 16, halve it, then take away 20. What number do you get?
- 21.Magic trick! Think of 14. Double it, add 4, halve it, then take away 14. What number do you get?
- 22.I thought of a number, added 3 and then doubled it. I got 46. What was my number?
- 23.I thought of a number, added 3 and then doubled it. I got 14. What was my number?
- 24.Think of 13. Multiply it by 3, then add 3. What number do you end with?
- 25.I thought of a number, multiplied it by 2 and added 1. I got 7. What was my number?
- 26.I thought of a number, multiplied it by 5 and added 7. I got 82. What was my number?
- 27.Think of 8. Multiply it by 2, then add 4. What number do you end with?
- 28.Think of 5. Multiply it by 5, then add 2. What number do you end with?
- 29.I thought of a number, multiplied it by 4 and added 5. I got 37. What was my number?
- 30.Magic trick! Think of 3. Double it, add 10, halve it, then take away 3. What number do you get?
- 31.Magic trick! Think of 6. Double it, add 14, halve it, then take away 6. What number do you get?
- 32.Think of 4. Multiply it by 5, then add 7. What number do you end with?
- 33.Magic trick! Think of 19. Double it, add 10, halve it, then take away 19. What number do you get?
- 34.Think of 4. Multiply it by 4, then add 5. What number do you end with?
- 35.Think of 2. Multiply it by 2, then add 9. What number do you end with?
- 36.Think of 4. Multiply it by 2, then add 1. What number do you end with?
- 37.Magic trick! Think of 6. Double it, add 18, halve it, then take away 6. What number do you get?
- 38.I thought of a number, added 5 and then doubled it. I got 50. What was my number?
- 39.I thought of a number, multiplied it by 3 and added 6. I got 24. What was my number?
- 40.I thought of a number, added 4 and then doubled it. I got 34. What was my number?
Answer key
- 7
- 5
- 29
- 7
- 8
- 20
- 4
- 8
- 13
- 23
- 20
- 3
- 6
- 21
- 4
- 35
- 24
- 10
- 9
- 8
- 2
- 20
- 4
- 42
- 3
- 15
- 20
- 27
- 8
- 5
- 7
- 27
- 5
- 21
- 13
- 9
- 9
- 20
- 6
- 13
Free maths tricks lessons, practice and worksheets at talentjr.in/maths-tricks