Divisibility by 8

How can we tell whether an integer is divisible by 8? If its last three digits form a number that is divisible by 8. If you cannot easily decide whether a three-digit number is divisible by 8, unfortunately you will have to use a calculator or work it out on paper. Examples:

• The number 6,315,648 is divisible by 8, because 648 is divisible by 8.
• The number 70,051 is not divisible by 8, because 051, that is, 51, is not divisible by 8.