 # 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`.