Life's Great Mystery

How come the numbers go from bottom to top on calculators:

 

and adding machines:

and computer keypads:

 

but from top to bottom on telephones:

 

and ATMs:

 

I'm sure someone out there will know. My money's on Dr. Momentum.

Comments

[Susan]

I do not know but I do know that IBM keypunch pads are like phones not computers and it was a BIG problem when we moved the data entry people to new technology. I'm aging myself I know. :-)

[Tonya]

I remember asking this question long ago when I first learned how to 10-key, and I recall the answer having to do with a patent. Whether that's true, I'm not sure!

[jo]

And our credit card machine at work. It drive me crazy!

[Will]

I've never understood why the 0 is after the 9 on phones, instead of before the 1.

[James]

I found this an interesting question, so i responded on my blog!

[Karen]

I knew I could count on you! :-) I still wonder why ATM manufacturers chose to copy telephone keypads instead of adding machines -- maybe because people are inputting passwords that are likely to have letters as well as numbers. (See James' post here: http://www.drmomentum.com/aces/archives/003733.html)

[Elena]

I always thought the 0 on phones came after the 9 because it really stood for 10. That seems dumb now that I've put that into words!

[Daisy OK]

These conflicting designs make it tough for people with visual impairments.