When archiving invoices and other receipts to your tax-administration there are always some receipts which do not have the correct VAT (BTW in Dutch) amounts noted.You need to get your calculator ( a real one or a widget), calculate the amounts with or without the VAT etc, etc… tedious!

Because I’m working with jQuery now anyway, I tought it should be pretty easy creating a calculator in HTML which has some functions built in to simplify this process.

And here it is (link opens in a popup)

Actually this thing turned out pretty neat. Apart from the VAT calculation – It’s also possible to input a complete formula in the display. Just click on the display screen to activate and start typing.

ofcourse you can type

707+707

and pressing enter calculates the result.

You can also enter this

 Math.sqrt((121+10)/445)*20

So, complete javascript formulas which you use on programming. Math.sqrt – that’s the square root command. Here’s an example list of what javascript is capable of.