Javascript display the last 3 numbers after the dot fixed(3) not working

I have a number which looks number this:

800.60000305176541

This number changes all the time.

So I’m doing this:

var mynumber = 800.60000305176541

var changenumber = mynumber.toFixed(3);

This is displaying 800.600 … I need it to display the last 3 like:

800.541

How can I do this?

Answer

You can convert to string and do your manipulations. Please note we are loosing the right most digit due to limits of javascript.

var num = 800.60000305176541;

var str = "" + num
var arr = str.split(".");
var result = arr[0]
if (arr[1]) {
  result += "." + arr[1].slice(-3)
}
console.log(num)
console.log(result)