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 4. Double it, add 18, halve it, then take away 4. What number do you get?
- 2.Magic trick! Think of 7. Double it, add 16, halve it, then take away 7. What number do you get?
- 3.Think of 12. Multiply it by 2, then add 2. What number do you end with?
- 4.I thought of a number, multiplied it by 5 and added 5. I got 25. What was my number?
- 5.Magic trick! Think of 18. Double it, add 18, halve it, then take away 18. What number do you get?
- 6.I thought of a number, multiplied it by 3 and added 1. I got 46. What was my number?
- 7.Magic trick! Think of 17. Double it, add 18, halve it, then take away 17. What number do you get?
- 8.Think of 11. Multiply it by 5, then add 7. What number do you end with?
- 9.Magic trick! Think of 17. Double it, add 6, halve it, then take away 17. What number do you get?
- 10.I thought of a number, multiplied it by 3 and added 5. I got 44. What was my number?
- 11.Magic trick! Think of 12. Double it, add 6, halve it, then take away 12. What number do you get?
- 12.Think of 13. Multiply it by 2, then add 3. What number do you end with?
- 13.Think of 13. Multiply it by 4, then add 9. What number do you end with?
- 14.Magic trick! Think of 11. Double it, add 18, halve it, then take away 11. What number do you get?
- 15.Magic trick! Think of 4. Double it, add 16, halve it, then take away 4. What number do you get?
- 16.I thought of a number, added 6 and then doubled it. I got 40. What was my number?
- 17.Magic trick! Think of 13. Double it, add 14, halve it, then take away 13. What number do you get?
- 18.Think of 7. Multiply it by 3, then add 6. What number do you end with?
- 19.Think of 4. Multiply it by 5, then add 3. What number do you end with?
- 20.I thought of a number, added 9 and then doubled it. I got 58. What was my number?
- 21.I thought of a number, added 4 and then doubled it. I got 30. What was my number?
- 22.Think of 9. Multiply it by 5, then add 4. What number do you end with?
- 23.Magic trick! Think of 3. Double it, add 4, halve it, then take away 3. What number do you get?
- 24.Magic trick! Think of 3. Double it, add 10, halve it, then take away 3. What number do you get?
- 25.Magic trick! Think of 6. Double it, add 14, halve it, then take away 6. What number do you get?
- 26.I thought of a number, added 6 and then doubled it. I got 28. What was my number?
- 27.I thought of a number, added 2 and then doubled it. I got 38. What was my number?
- 28.I thought of a number, multiplied it by 3 and added 6. I got 12. What was my number?
- 29.Magic trick! Think of 9. Double it, add 12, halve it, then take away 9. What number do you get?
- 30.Magic trick! Think of 11. Double it, add 10, halve it, then take away 11. What number do you get?
- 31.I thought of a number, added 8 and then doubled it. I got 24. What was my number?
- 32.I thought of a number, added 5 and then doubled it. I got 44. What was my number?
- 33.Think of 6. Multiply it by 2, then add 7. What number do you end with?
- 34.I thought of a number, multiplied it by 5 and added 5. I got 45. What was my number?
- 35.Think of 13. Multiply it by 2, then add 7. What number do you end with?
- 36.Magic trick! Think of 7. Double it, add 10, halve it, then take away 7. What number do you get?
- 37.Magic trick! Think of 4. Double it, add 6, halve it, then take away 4. What number do you get?
- 38.I thought of a number, multiplied it by 3 and added 4. I got 16. What was my number?
- 39.I thought of a number, multiplied it by 4 and added 2. I got 34. What was my number?
- 40.I thought of a number, multiplied it by 2 and added 6. I got 26. What was my number?
Answer key
- 9
- 8
- 26
- 4
- 9
- 15
- 9
- 62
- 3
- 13
- 3
- 29
- 61
- 9
- 8
- 14
- 7
- 27
- 23
- 20
- 11
- 49
- 2
- 5
- 7
- 8
- 17
- 2
- 6
- 5
- 4
- 17
- 19
- 8
- 33
- 5
- 3
- 4
- 8
- 10
Free maths tricks lessons, practice and worksheets at talentjr.in/maths-tricks