Understand the number type in JavaScript (sign | exponent | significand)

This video starts off with an overview of the number type in JavaScript and then goes in depth so that you understand what happens under the hood.

You will learn things such as:
-why there are safe integers and unsafe integers in JavaScript
-what exactly is infinity
-why is there a +0 and -O in the language
-what is Not-a-Number (NaN)

All of these number types are explained by looking at the structure of number values in memory and by looking at examples. This is the only way to understand why numbers behave the way they do.

[simonshurety]

When the Max Safe Integer starts rounding up, say like 96 in your example is it totally random if it will round up or down? And what exactly is it rounding up/down?