How can you tell whether a number is divisible by another number (leaving no remainder) without actually doing the division.
If the last digit is even.
If the sum of the digits is divisible by 3.
If the last two digits form a number divisible by 4.
If the last digit is a 5 or a 0.
If the number is divisible by both 3 and 2.
If the last three digits form a number divisible by 8..
If the sum of the digits is divisible by 9, the number is also.
If the number ends in 0.