Integers (Proof)

Question 1

How can you tell if a number is divisible by 2

Answer 1

If the units are divisible by 2

Question 2

How can you tell if a number is divisible by 4

Answer 2

If the numbers last 2 digits are divisible by 4

E.g 57324 is divisible by 4 as 24 is divisible by 4

Question 3

How can you tell if a number is divisible by 8

Answer 3

If the last 3 digits are divisible by 8 the number is divisible by 8

E.g 4128, 128 can be divided by 8, so the whole number can be divided by 8

Question 4

How can you tell if a number is divisible by 9

Answer 4

If the sum of the numbers digits are divisible by 9, the number is divisible by 9

Question 5

How can you tell if a number is divisible by 3

Answer 5

If its digit sum is a multiple of 3, the number is divisible by 3

Question 6

How can you tell if a number is divisible by 6

Answer 6

It is divisible by both 2 and 3

Question 7

How can you tell if a number is divisible by 5

Answer 7

Its 1’s unit is a 5 or 0

Question 8

How can you tell if a number is divisible by 10

Answer 8

Its 1’s unit is a 0