# What is the Math Library?

JavaScript has a built-in Math library that I found very helpful many times already (refer to a few of my algorithm review problems). Math is a built-in object, not a function. It has properties and methods of static mathematical constants and functions.

**Math.ceil(x)**This method rounds a number (usually a decimal) upwards to its nearest integer and returns the result. If the number**x**is an integer then there will be nothing to round.`Math.ceil(1.4) // -> 2`

Math.ceil(2) // -> 2**Math.floor(x)**This method is the opposite of Math.ceil(x). It rounds the decimal number downwards to the nearest integer and returns the result.`Math.floor(1.6) // -> 1`

Math.floor(1) // -> 1**Math.PI**This is a property that returns the value of pi (3.14159….). This helps whenever you’re trying to calculate the circumference of a circle when it’s ever necessary. I used to be obsessed with the value of pi when I was a kid so I enjoy this property existing.**Math.pow(x,y)**This method returns the value of**x**to the power of**y**. We are also able to use the******operator to do the same thing. The issue with ** operand is that it isn’t compatible with Internet Explorer.**Math.pow(x,y)**gives us cross-browser support.`Math.pow(2,3) // -> 8`

2 ** 3 // -> 8**Math.sign(x)**This method checks if a number is negative, positive, or zero. If it’s negative, it returns -1. If it’s positive, it returns 1. If it’s zero, it returns 0. I found this method really useful on one of my previous LeetCode algorithm problems.`Math.sign(3) // -> 1`

Math.sign(-5) // -> -1

Math.sign(0) // -> 0