Earlier quoted context omitted.
Same, but I'm really fast at typing numbers without a numpad. I find moving my hand to a separate location just for numbers is a lot slower. Imo most people that could learn to type numbers quickly without a numpad as well. I wonder what the mechanics of some people typing faster on a numpad are, like how does the layout help over having them aligned in a row? Maybe there's less overlap when moving fingers?
It's a shared skill with calculators (including those with printer tape, which auditing groups seem to adore), and it seems to have the side effect of high keying rates sustained over time. With a centering mark in the middle of the pad, and only the need to move fingers forwards and backwards (no sideways motion), sustained input of 10,000 digits per hour, with 0 mistakes, is not just possible to expected.
For me I find that typing numbers with the top row the home keys for the letters are still useful for centering to move between letters and numbers.
Couldn't you argue only having to move sideways for typing is more efficient than having to move forwards and backwards? Plus you can use two hands to divide the digits between left and right hand.