Number rounding in Javascript

Javascript helps lay the foundation for rounding off numbers with the following method:

Math.round (x)

Using this expression, any supplied argument is rounded off to the nearest integer by utilizing the ".5" up rule:

Math.round(25.9) //returns 26
Math.round(25.2) //returns 25
Math.round(-2.58) //returns -3

Let us say you would like to display $25 in standard currency format or PI to infinity. Formatting numbers to specific decimal points utilizes Math.round(), but padded with a little multiplication and division:

var original=28.453

1//round "original" to two decimals
var result=Math.round(original*100)/100 //returns 28.45

2// round "original" to 1 decimal
var result=Math.round(original*10)/10 //returns 28.5

3//round 8.111111 to 3 decimals
var result=Math.round(8.111111*1000)/1000 //returns 8.111

The formula to round any number to x decimal points is:

1) Multiple the original number by 10^x (10 to the power of x)
2) Apply Math.round() to the result
3) Divide result by 10^x