Is 21 Divisible By 7?
Here we will show you how to find out if 21 is divisible by 7.
If you have access to a calculator, the easiest way to figure out if 21 is divisible by 7 may be to simply enter 21/7 into the calculator. If the quotient is an integer, then 21 is divisible by 7.
However, you can also determine if 21 is divisible by 7 using an alternate method.
Simply multiply the last digit by 2 and then subtract the product from the remaining digits.
If that difference is divisible by 7, then 21 is divisible by 7.
The last digit in 21 is 1 and the remaining digits are 2. Thus, the math to determine if 21 is divisible by 7 using our alternate method is:
2 - (1 x 2) = 0
Since 0 is divisible by 7, 21 is also divisible by 7.
Therefore, the answer to "Is 21 Divisible By 7?" is yes.
(21 / 7 = 3)
Terminology
Words we used to explain if 21 is divisible by 7 that you may find useful:
Quotient: The answer you get when you divide two numbers.
Integer: A whole number.
Product: The answer you get when you multiply two numbers.
Difference: The answer you get when you subtract one number from another.