Use factors of a number to aid mental computation involving multiplication and division, eg to multiply a number by 12, first multiply the number by 6 and then multiply the result by 2
| 1. | Number Detectives: Prime a + prime b=15 | |
| 2. | Number Detectives: b-a=8, ab=20 | |
| 3. | Number Detectives: a+b=19, ab=84 | |
| 4. | Number Detectives: a+b=13, ab=42 | |
| 5. | Number Detectives: a+b=12, ab=32 | |
| 6. | Number Detectives: A number + its square = 30 (2 integers) | |
| 7. | Number Detectives: a+b=15 Highest value of product? | |
| 8. | Number Detectives: Sum of 4 consecutive odd nos = 40 | |
| 9. | Number Detectives: Sum of 4 consecutive odd nos = 120 | |
| 10. | Number Detectives: Sum of 4 consecutive even nos = 60 | |
| 11. | Number Detectives: ab= 126 a+b= 25 | |
| 12. | Number Detectives: Sum of 4 consecutive odd nos = 80 | |
| 13. | Number Detectives: a+b=17, ab=-60 | |
| 14. | Number Detectives: a+b=55, ab=484 | |
| 15. | Number Detectives: a+b=133, ab=1000 | |
| 16. | Number Detectives: 2 prime numbers-sum =1 more than 8 squared | |
| 17. | Number Detectives: prime cubed + prime = 127 | |
| 18. | Number Quest - complete number sentence | |
| 19. | Logical Leaps - sum and product | |
| 20. | Logical Leaps - sum and product | |
| 21. | Logical Leaps - sum and product | |
| 22. | Logical Leaps - product of consecutive numbers |