The reason I like about the game Factor Captor is because it makes you familiar with factors and prime numbers. I like the way the game is scored and how you can only use the same number once. It really makes me think a lot. I liked using the biggest prime numbers on the board since they had only two factors, 1 and itself. If you chose 2 which is a prime number, then your opponent would get 1 since 1 is a factor of 2, you only gain 1 point, so you might as well use 10.
Making an array might help you find some factors when your opponent chooses a big number since you can count the array's rows and columns to find two of the number's factors. If you continue to make more arrays for the same number without using the same factor twice, you can find all the factors of the number of dots in the array.
In the pages 2-28 in my math journal, my favorite exercise was finding the divisibility rules for each number. It made dividing big numbers easy. I learned that if the numbers digits added up to a multiple of 3 or 9, the entire number is divisible by 3 or 9 depending on which number the digits could be divisible by. I also learned that if the last two digits are divisible by four, the entire number is divisible by four. Lastly, I learned that if the number is divisible by 2 and 3, the number is divisible by 6.