Teacher Notes
X
TIMS Challenge
This DPP item can be used as a Problem of the Week.
60, 72, 84, 90, and 96 all have 12 factors.
Possible response: First I eliminated the odd numbers since they have fewer factors. Then I eliminated numbers 10 or less because they have few factors. I then looked for numbers that are divisible by more than 3 primes (e.g., 2, 3, 5, 7). These would likely have the most factors.
L. How Many Factors 
The number 100 has the following nine factors: 1, 2, 4, 5, 10, 20, 25, 50, and 100. Which numbers from 1 to 100 have the most factors? Show or tell how you know.
Describe your strategy.
- Which numbers did you eliminate without factoring?
- How did you use the divisibility rules?
