05 - Number Properties

Question 1

How do you know an integer is divisible by the following number: 6

Answer 1

If integer is divisible by both 2 and 3

Question 2

How do you know an integer is divisible by the following number: 7

Answer 2

There’s no trick; must perform long division

Question 3

How do you know an integer is divisible by the following number: 8

Answer 3

If the integer is div by 3 three times, or if the last three digits are divisible by 8.

Question 4

How do you know an integer is divisible by the following number: 9

Answer 4

If the sum of the integer’s digits are divisible by 9 (same rule applies to 3)

Question 5

How do you know an integer is divisible by the following number:

4

Answer 5

If divisible by 2 twice, or last two digits are div by 4