Signs of divisibility by 2, 4 and 8

To understand whether one number is divisible by another it is not necessary to carry out complex calculations or to have a calculator with you. Mathematicians have come up with special rules that will help you find out if numbers are completely divided into each other. These rules are called signs of divisibility .

Sign of divisibility by 2

A number is divisible by 2 if its last digit is divisible by 2 or is zero.

Examples:

• 52 is divisible by 2. The last digit 2 is divisible by 2 completely (2: 2 = 1).
• 300 is divisible by 2. Last digit is 0.
• 11 is not divisible by 2. Last digit 1 is not divisible by 2.

Sign of divisibility by 4

A number is divisible by 4 if its last two digits are zeros or form a number divisible by 4.

Examples:

• 548 is divisible by 4. The last two digits of 48 are divisible by 4 (48: 4 = 12).
• 600 is divisible by 4. The last two digits are zeros.
• 755 is not divisible by 4. The last two digits 55 are not divisible by 4.

Sign of divisibility by 8

A number is divisible by 8 if the last three digits of it are zeros or form a number divisible by 8.

Examples:

• 1128 is divisible by 8. The last three digits 128 are divisible by 8 completely (128: 8 = 16).
• 7000 is divisible by 8. The last three digits are zeros.
• 6755 is not divisible by 4. The last three digits 755 are not divisible by 8.