# 12.5. Math Methods¶

As with strings and arrays, JavaScript provides some built-in methods for the `Math` object. These allow us to perform calculations or tasks that are more involved than simple multiplication, division, addition, or subtraction.

## 12.5.1. Common Math Methods¶

The `Math` object contains over 30 methods. The table below provides a sample of the most frequently used options. More complete lists can be found here:

To see detailed examples for a particular method, click on its name.

Ten Common Math Methods

Method

Syntax

Description

abs

`Math.abs(number)`

Returns the positive value of `number`.

ceil

`Math.ceil(number)`

Rounds the decimal `number` UP to the closest integer value.

floor

`Math.floor(number)`

Rounds the decimal `number` DOWN to the closest integer value.

max

`Math.max(x,y,z,...)`

Returns the largest value from a set of numbers.

min

`Math.min(x,y,z,...)`

Returns the smallest value from a set of numbers.

pow

`Math.pow(x,y)`

Returns the value of x raised to the power of y (x y).

random

`Math.random()`

Returns a random decimal value between 0 and 1, NOT including 1.

round

`Math.round(number)`

Returns `number` rounded to the nearest integer value.

sqrt

`Math.sqrt(number)`

Returns the square root of `number`.

trunc

`Math.trunc(number)`

Removes any decimals and returns the integer part of `number`.

## 12.5.2. Check Your Understanding¶

Follow the links in the table above for the `floor`, `random`, `round`, and `trunc` methods. Review the content and then answer the following questions.

Question

Which of the following returns `-3` when applied to `-3.87`?

1. `Math.floor(-3.87)`

2. `Math.random(-3.87)`

3. `Math.round(-3.87)`

4. `Math.trunc(-3.87)`

Question

What is printed by the following program?

 ```1 2 3``` ```let num = Math.floor(Math.random()*10); console.log(num); ```
1. A random number between 0 and 9.

2. A random number between 0 and 10.

3. A random number between 1 and 9.

4. A random number between 1 and 10.

Question

What is printed by the following program?

 ```1 2 3``` ```let num = Math.round(Math.random()*10); console.log(num); ```
1. A random number between 0 and 9.

2. A random number between 0 and 10.

3. A random number between 1 and 9.

4. A random number between 1 and 10.