There are a few extensions out there that can help to format a number, but I thought I would have a go just using blocks. The resulting aia project file allows the user to select a currency emblem to go in front of the number, numbers larger than 999 are given commas between each 000, and any decimals at then end of the number can be formatted to preferred number of decimal places or not shown (rounding up not handled for this last one). The output is returned to a label, and of course, with all the formatting, it is no longer a number but a string!

BLOCKS

AIA

NumberFormatter.aia