[Closi]

Because these are businesses that are probably using a calculator anyway.

It's very much a cultural thing - punch numbers into the calculator and pass it back and forth when negotiating on a price, or add up the costs on a physical calculator on your market stall. You aren't giving receipts or anything, so hard to keep track.

I'm in the UK so don't see it often, but if you go to India / Vietnam / Thailand etc you see lots of people punching numbers into calculators everywhere rather than using some sort of POS system.

Asking why you don't just use your phone with a numberpad is missing that the selling point here is that the user interface IS a calculator.

[aniforprez]

One of the big draws is a tactile interface that you don't have to look at while you punch in the numbers. Smartphone touch screens don't offer that and brick phones are too dumb or the models that do have some form of smart OS are not available in these places. This seems like a good way to tap into an existing market that's fairly huge while adding smart features