Roeshimi Paypal also has it like this, you write the digits from the right side. But, for me it seems to be more complicated, because 10EUR or 20EUR would then have to be written as 1000 or 2000, while I now write 10 or 20 -> pay. If I would like to pay a invoice with 10,23, I would have to write 1023 in your version, and actual 10,23. So in most cases, where the amounts are rounded to the full EUR, the new version would need the additional input of two 00. And on the other case, entering EUR and cent, you have to input 4 digits in the new version: 1023 or in the actual version 4 digits and a comma: 10,23. You save one sign/letter.
I'm not convinced. In most cases entering 10 or 20 is faster for me.