Why are the numbers on keyboard numpads are not arranged like ATM or phone keypads? [closed]

The second link that slhck posted hits it right on the head. The keyboard number pad has the layout it does because that's the same way a calculator is laid-out. The idea was that accountants and others who frequently-used calculators would find it easier to use the number pad, as opposed to the numbers off of the top row.

As a developer, I always hit numbers off of the top-row of the keyboard. On the other hand, I have two friends who are CPAs and they frequently use the number pad...and they are incredibly fast when they do it.

Try labeling a calculator keypad with the letters A-Z in the same way they're arranged on a telephone keypad (taken from the old dial telephones) and typing something like 1-800-GET-SPAM. You'll find that the alphabet is reversed in 3-letter chunks. That's what the old Bell Labs test was about - speed of typing alphabetic "phone numbers" on different key layouts. If they had used a calculator format, all the companies with mnemonic phone numbers would have been up in arms.