I use the number pad on my keyboard to type numbers a lot of the time (when I’m not using the laptop, in which case I never enable it). I’ve also been on a lot of conference calls lately. I know – I’m extraordinarily lucky, but this is not intended to make you insanely jealous, so I’ll move on.

As many who have come before me have noticed, the number pad displays the numbers with zero at the bottom and 1, 2 and 3 in the next row closest to the bottom. Telephones display 1, 2 and 3 in the top row (and *, 0 and # in the bottom row). This is an annoying discrepancy when one such as I, lucky that I am, goes from typing a series of numbers into the number pad, for whatever reason, then must punch in a phone number, particularly when one such as I must read the number off the screen and is not looking at the phone. Oh! the numbers I try to dial.

So why is this? Here’s my best guess.

Calculators.

I’ll wait for you to put your socks back on (now that I’ve blown them off with this revelation). The push button telephone was developed in the early 40s and put into commercial circulation in the early 60s (thank you, Wikipedia). I don’t know what the delay was for, although Wikipedia notes that the boys at AT&T conducted studies in the 50s that found that push button was faster than rotary. I don’t think we needed a study to determine that, but it was an exciting, scary time so I’m sure hard data was reassuring to everyone involved. If you look at a telephone interface (buttonface?) and contemplate dialing, it makes sense to start at the top and work your way down. We (Westerners) read left-to-right and top-to-bottom. This set-up makes sense.

So calculators. Solid-state calculators were developed in the 60s. Before that there were all kinds of calculators and adding machines that were hand operated (or even electrical). But most of them evolved into a form that looks kind of like a typewriter. I don’t know when the buttons became standardized, but you and I can easily imagine that when you’re using an adding machine – those laborious creatures – on your desk day in and day out, it makes sense to start at the bottom and work your way up to the higher numbers, because that’s where your interaction begins from – the bottom. This is easiest to imagine, I think, if you picture one of those big old adding machines that bankers (and accountants, I suppose) sometimes still have on their desks. You have the beginning of the numbers close at hand, and they recede from you. The reverse would be rather like if the keypad were the preface to Star Wars, and you have to start reading at the top (tiny) row once the entire preface is on-screen, rather than reading from the bottom up, which we do since the words scroll – unless you come in late and then you’re stuck squinting. Or, when you’re driving, and there are helpful words printed on the roadway, like “STOP AHEAD” and “TURN ONLY.” Read top-to-bottom, these read “AHEAD STOP” and “ONLY TURN” – but we read them correctly because we read the words in the order we drive over them, not from top-to-bottom. But I digress.

So back on topic, both interfaces (telephone and calculator, which is the basis of the number pad on the keyboard) make sense for the user. It’s actually quite lovely to contemplate – something made for the best use of the user, and not based on similar-looking things.