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Comment by lm28469 | Hacker News Reader

> I know this is a bit of a shortcut but have pocket calculators rendered mental math extinct?

I've witness several cashiers getting their phone out to calculate basic change. Things like 1 euros - 20ct

So yes definitely

While people should be able to calculate basic change in their head, especially if they're working with cash, when I worked in banking, we had explicit policies for cashiers to never ever do that in their head, no matter how simple, because the error rates are meaningfully different. A tired person in a hurry will occasionally get a brainfart and calculate something like 80-33 = 57 or pay out 200 as 20 times 20, so the policy was that you have to get the machine to calculate even the simplest stuff always.

When doing a math problem on an exam, I would always type in very simple intermediate calculations. Avoiding silly mistakes was part of the reason, but it was also so I could look through the calculator history when checking my work and see where each number came from. I would probably be inclined to do the same if I was a bank teller.

Being able to do basic math is definitely good, but I don't think that's nearly as bad as not knowing how to write without an AI. A cashier can reasonably expect to only need to work with a cash register in front of them, but if you can't write, you can't communicate your own ideas. And sometimes in life you are going to need to communicate and support your ideas, not just whatever the AI decides to spit out for that prompt.

I agree, but I'm also certain that using an AI writer will actually teach you to write better - like with art generators, you still need to look at the result and recognize it as good/better, and you form your taste by iterating.

I'm thinking about this from a McLuhanesque perspective, i.e. how the medium will shape the user, and in this case learning to write by going through large amounts of generated writing is just a more efficient way than the regular way (reading, getting own output graded, etc.).

> I've witness several cashiers getting their phone out to calculate basic change.

Don't point-of-sale devices do that already? The cashier inputs the total you gave them, and the point-of-sale device shows the exact change on its screen (and releases the cash drawer lock). It might seem useless, but it reduces the risk of an incorrect mental calculation (like R$ 100 - R$ 77 => R$ 33 instead of R$ 23). Some even display which coins and notes, and how many of each, the cashier should get for the change.

Well, I said extinct, but I wouldn't bet that on average mental arithmetic skills went down, perhaps they have, on the other hand it freed people up for learning about more complex operations and allowing them to perform those operations where otherwise they would be too costly.

Why not mitigate both, force people to learn the basics, allow them to use the tools later.

It isn't mutually esclusive

At least in math they didn't learn those operations though, because they don't have a strong foundation in the basics to understand how it works. Mental arithmetic is often indicative of at least a somewhat stronger number sense, and this shows at upper level math courses. Even at the high school level, where I had to struggle with kids who were way too reliant on a calculator and couldn't do basic math because of it, and thus struggled to do anything more advanced or abstract.

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