# Checking the division remainder in JavaScript

Suppose we have two variables with numbers:

`let a = 10; let b = 3;`

Let's find the remainder after dividing one variable by another:

`let a = 10; let b = 3; console.log(a % b); // shows 1`

Let now the variables store such values that one variable is divided by the second completely:

`let a = 10; let b = 5; console.log(a % b); // shows 0`

Let's write a script that will check if one number is divisible by the second:

`let a = 10; let b = 3; if (a % b === 0) { console.log('is divisible'); } else { console.log('is divided with a remainder'); }`

Let now it is required, if the number is divided with the remainder, output this remainder to the console:

`let a = 10; let b = 3; if (a % b === 0) { console.log('is divisible'); } else { console.log('is divided with a remainder ' + a % b); }`

In the code above, it turns out that the remainder is calculated in two places, and this is not optimal. Let's fix the problem:

`let a = 10; let b = 3; let rest = a % b; if (rest === 0) { console.log('is divisible'); } else { console.log('is divided with a remainder ' + rest); }`

As you know, even numbers are divided by `2` without a remainder, and odd numbers with a remainder. Let's say you have a number. Use the operator `%` and the construct `if` to check if this number is even or not.

Given a number. Check that it is divisible by `3`.

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