So many forks for something that can be solved entirely with bash inbuilts

Please put your code between tripple backticks in a seperate line above an below your code. Single backticks are only for inline code like this.

To answer your question, the %.2f means it should only print two digits after the decimal point.

You can also use some other variations like this:

• %2f print the number at least 2 characters wide
• %5.2 print the number at least 5 characters wide with a precision of two digits after the decimal point
• %05.2 the same as above, but fill leading digits with zeros

This is just formatting, play a bit around with it and you will get it.