# The `Math.round` function

## Produces an error when passed an argument of incorrect type

### Juttle

    emit -from Date.new(0) -limit 1 | put result = Math.round(null) | view result

### Warnings

  * Invalid argument type for "Math.round": expected number, received null.

## Produces an error when passed a digits argument of incorrect type

### Juttle

    emit -from Date.new(0) -limit 1 | put result = Math.round(1, null) | view result

### Warnings

  * Invalid argument type for "Math.round": expected number, received null.

## Rounds numbers to specified digits

### Juttle

    const examples =
        Math.round(55.55, 1) == 55.6 &&
        Math.round(55.549, 1) == 55.5 &&
        Math.round(55, -1) == 60 &&
        Math.round(54.9, -1) == 50 &&
        Math.round(-55.55, 1) == -55.5 &&
        Math.round(-55.551, 1) == -55.6 &&
        Math.round(-55, -1) == -50 &&
        Math.round(-55.1, -1) == -60 &&
        Math.round(1.005, 2) == 1.01;

    emit -from Date.new(0) -limit 1
    | put winning = examples | keep winning | view result

### Output

    { winning: true }