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.Think of 6. Multiply it by 5, then add 3. What number do you end with?
- 2.Think of 6. Multiply it by 3, then add 8. What number do you end with?
- 3.I thought of a number, multiplied it by 3 and added 9. I got 30. What was my number?
- 4.Think of 11. Multiply it by 5, then add 2. What number do you end with?
- 5.Think of 7. Multiply it by 2, then add 1. What number do you end with?
- 6.Think of 14. Multiply it by 3, then add 2. What number do you end with?
- 7.I thought of a number, added 4 and then doubled it. I got 18. What was my number?
- 8.Think of 14. Multiply it by 3, then add 1. What number do you end with?
- 9.I thought of a number, added 7 and then doubled it. I got 28. What was my number?
- 10.Magic trick! Think of 11. Double it, add 18, halve it, then take away 11. What number do you get?
- 11.I thought of a number, multiplied it by 5 and added 3. I got 78. What was my number?
- 12.Think of 9. Multiply it by 2, then add 5. What number do you end with?
- 13.I thought of a number, multiplied it by 5 and added 5. I got 30. What was my number?
- 14.I thought of a number, added 8 and then doubled it. I got 50. What was my number?
- 15.Magic trick! Think of 17. Double it, add 16, halve it, then take away 17. What number do you get?
- 16.Magic trick! Think of 3. Double it, add 4, halve it, then take away 3. What number do you get?
- 17.Magic trick! Think of 4. Double it, add 18, halve it, then take away 4. What number do you get?
- 18.Think of 13. Multiply it by 4, then add 5. What number do you end with?
- 19.Magic trick! Think of 13. Double it, add 16, halve it, then take away 13. What number do you get?
- 20.Think of 2. Multiply it by 2, then add 1. What number do you end with?
- 21.Think of 14. Multiply it by 2, then add 8. What number do you end with?
- 22.I thought of a number, added 1 and then doubled it. I got 18. What was my number?
- 23.Magic trick! Think of 10. Double it, add 16, halve it, then take away 10. What number do you get?
- 24.Magic trick! Think of 11. Double it, add 12, halve it, then take away 11. What number do you get?
- 25.I thought of a number, added 4 and then doubled it. I got 22. What was my number?
- 26.I thought of a number, multiplied it by 2 and added 2. I got 30. What was my number?
- 27.I thought of a number, added 1 and then doubled it. I got 26. What was my number?
- 28.Think of 4. Multiply it by 4, then add 5. What number do you end with?
- 29.I thought of a number, multiplied it by 3 and added 4. I got 34. What was my number?
- 30.Think of 13. Multiply it by 3, then add 1. What number do you end with?
- 31.I thought of a number, multiplied it by 4 and added 2. I got 42. What was my number?
- 32.Magic trick! Think of 4. Double it, add 6, halve it, then take away 4. What number do you get?
- 33.I thought of a number, added 4 and then doubled it. I got 42. What was my number?
- 34.I thought of a number, multiplied it by 2 and added 8. I got 18. What was my number?
- 35.Magic trick! Think of 11. Double it, add 8, halve it, then take away 11. What number do you get?
- 36.I thought of a number, multiplied it by 2 and added 3. I got 31. What was my number?
- 37.I thought of a number, added 4 and then doubled it. I got 36. What was my number?
- 38.Think of 12. Multiply it by 3, then add 3. What number do you end with?
- 39.I thought of a number, multiplied it by 5 and added 5. I got 45. What was my number?
- 40.I thought of a number, multiplied it by 5 and added 4. I got 29. What was my number?
Answer key
- 33
- 26
- 7
- 57
- 15
- 44
- 5
- 43
- 7
- 9
- 15
- 23
- 5
- 17
- 8
- 2
- 9
- 57
- 8
- 5
- 36
- 8
- 8
- 6
- 7
- 14
- 12
- 21
- 10
- 40
- 10
- 3
- 17
- 5
- 4
- 14
- 14
- 39
- 8
- 5
Free maths tricks lessons, practice and worksheets at talentjr.in/maths-tricks