How do you decide if a two digit number is a multiple of a one-digit number?

If the number is even, it is a multiple of 2

If the sum of the digits make a number divisible by 3, the number is a multiple of 3

If the number ends in 5 or 0, the number is a multiple of 5

If the number is divisible by 2 and 3, the number is a multiple of 6

If the sum of the digits make a number divisible by 9, the number is a multiple of 9