Chapter Review: #5

a) How do you know that 210 is divisible by 2, 5, and 10?
Answer - 2 goes into every even numbers, 5 ends with either a 0 or 5, 10 just ends with a 0.

b) How do you know 1232 is divisible by 4 and 8?
Answer - 4 goes into the number two times (2+2=4), 8 goes into it thrice (2+2+2=8).

c) How do you know that 333 is divisible by 3 and 9 but not by 6?
Answer - 3 goes into it after you add the numbers up and get the sum. Same rule for 9, 6 needs 2 and 3 for it to fit.