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, multiplied it by 2 and added 2. I got 10. What was my number?
- 2.Think of 2. Multiply it by 2, then add 8. What number do you end with?
- 3.Think of 4. Multiply it by 2, then add 5. What number do you end with?
- 4.I thought of a number, added 1 and then doubled it. I got 28. What was my number?
- 5.I thought of a number, multiplied it by 2 and added 9. I got 21. What was my number?
- 6.I thought of a number, multiplied it by 5 and added 2. I got 72. What was my number?
- 7.Magic trick! Think of 6. Double it, add 14, halve it, then take away 6. What number do you get?
- 8.Magic trick! Think of 18. Double it, add 14, halve it, then take away 18. What number do you get?
- 9.Think of 10. Multiply it by 5, then add 9. What number do you end with?
- 10.Magic trick! Think of 14. Double it, add 14, halve it, then take away 14. What number do you get?
- 11.Magic trick! Think of 17. Double it, add 18, halve it, then take away 17. What number do you get?
- 12.I thought of a number, added 6 and then doubled it. I got 34. What was my number?
- 13.Magic trick! Think of 15. Double it, add 14, halve it, then take away 15. What number do you get?
- 14.Think of 5. Multiply it by 4, then add 4. What number do you end with?
- 15.Think of 3. Multiply it by 2, then add 3. What number do you end with?
- 16.I thought of a number, multiplied it by 3 and added 7. I got 13. What was my number?
- 17.Think of 15. Multiply it by 2, then add 4. What number do you end with?
- 18.I thought of a number, multiplied it by 3 and added 4. I got 13. What was my number?
- 19.I thought of a number, multiplied it by 2 and added 7. I got 23. What was my number?
- 20.I thought of a number, added 7 and then doubled it. I got 20. What was my number?
- 21.Think of 11. Multiply it by 3, then add 4. What number do you end with?
- 22.I thought of a number, added 7 and then doubled it. I got 34. What was my number?
- 23.Magic trick! Think of 18. Double it, add 8, halve it, then take away 18. What number do you get?
- 24.I thought of a number, multiplied it by 5 and added 9. I got 24. What was my number?
- 25.Think of 2. Multiply it by 5, then add 4. What number do you end with?
- 26.I thought of a number, added 2 and then doubled it. I got 24. What was my number?
- 27.I thought of a number, added 9 and then doubled it. I got 52. What was my number?
- 28.Think of 9. Multiply it by 5, then add 1. What number do you end with?
- 29.Magic trick! Think of 17. Double it, add 4, halve it, then take away 17. What number do you get?
- 30.Magic trick! Think of 7. Double it, add 6, halve it, then take away 7. What number do you get?
- 31.Magic trick! Think of 2. Double it, add 12, halve it, then take away 2. What number do you get?
- 32.Think of 11. Multiply it by 2, then add 9. What number do you end with?
- 33.Think of 14. Multiply it by 5, then add 1. What number do you end with?
- 34.Magic trick! Think of 12. Double it, add 18, halve it, then take away 12. What number do you get?
- 35.Think of 6. Multiply it by 5, then add 3. What number do you end with?
- 36.Magic trick! Think of 4. Double it, add 12, halve it, then take away 4. What number do you get?
- 37.I thought of a number, added 5 and then doubled it. I got 44. What was my number?
- 38.Magic trick! Think of 3. Double it, add 16, halve it, then take away 3. What number do you get?
- 39.Magic trick! Think of 2. Double it, add 16, halve it, then take away 2. What number do you get?
- 40.I thought of a number, added 7 and then doubled it. I got 36. What was my number?
Answer key
- 4
- 12
- 13
- 13
- 6
- 14
- 7
- 7
- 59
- 7
- 9
- 11
- 7
- 24
- 9
- 2
- 34
- 3
- 8
- 3
- 37
- 10
- 4
- 3
- 14
- 10
- 17
- 46
- 2
- 3
- 6
- 31
- 71
- 9
- 33
- 6
- 17
- 8
- 8
- 11
Free maths tricks lessons, practice and worksheets at talentjr.in/maths-tricks