[gosub100]

I dont know what you mean by aligned right (if it aligned left it would have to know how much you intended to transfer before you started), but wells fargo web (and I think app) uses this, and I prefer it for making small payments. They know you're going to type the decimal anyway, so they save you a step. I get mildly annoyed that other banking sites make me type it. If I'm paying $83.21 I still have to type 4 digits, why not save me the step?

[paledot]

When I've encountered it, the interface has looked like this (as I'm in the process of filling it in):

    $_.__
    $_._1
    $_.12
    $1.23
    $12.34

Typically it also rejects non-numeral inputs, so if you muscle-memory a decimal point it gets ignored and your input (hopefully) proceeds normally. Whereas a "left-aligned" input would be the style that we're accustomed to from general text input:

    $
    $1
    $12
    $12.
    $12.3
    $12.34

[ipqk]

Because lots of people send mostly whole numbers to friends and family. If I want to send $5 instead of typing "5" I now have to type "500"

[constantly]

I’m confused by the “aligned left” comment. Analogously this seems like saying left alignment in my word processor would mean the word processor would need to know what I was going to type before I type it.

Can you explain?