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Why would anyone be good at arithmetic? Who does their own arithmetic? I understand that before smartphones it was less common to have a calculator in your lit

Why would anyone be good at arithmetic? Who does their own arithmetic? I understand that before smartphones it was less common to have a calculator in your literal pocket all the time, but you’d have one at work. You’d have one doing your taxes. Even you child would have one at the bottom of the toy box or left on the floor somewhere. That was the state of things for decades. I recently taught my daughter long division. Home schooling; it’s a requirement. I have to be honest, so I can’t tell her it’s important. She wants to know why it’s in the requirements. My best guess is that it was a job skill in the 1970s and that the education system has a lot of bureaucratic inertia.

erehweb 5y ago
While you certainly can calculate everything easily on a calculator, I think there's a value to being able to do your own arithmetic easily, in that this transfers over to good estimation skills and having a sense for when you typed the wrong thing into the calculator. Not something I have a proof of, though.
- BeFlatXIII 5y ago
  My teachers used to call that intuition "number sense".
kragen 5y ago
I did long division on paper yesterday, to convert swimming-pool evaporation rates given as millimeters per day to nanometers per second. Probably a skill I use every week or two. It's true that I could do it faster with a calculator. Perhaps a more practical example was that the day before yesterday my father told me that the recent collapse of an ice shelf off Antarctica was likely to raise sea levels by 27 inches in the next three to five years by debuttressing [what turned out to be] the Thwaites Glacier, so possibly the seaside camping spot he was enjoying that day would be under a foot of water in a few years. I immediately protested that this could not be correct; he must have misunderstood the research, because it was the wrong order of magnitude for such a short time period. And in fact it was the wrong order of magnitude, and the article he had read was deliberately sensationalized by juxtaposing sea-level rises that might occur over the next 80 years with events that will happen over the next three to five years. So his campsite will be fine. Didn't need mental long division for that, though.
- wrycoder 5y ago
  I’m terrible at arithmetic, but one very useful skill I have (probably left over from my slide rule days) is doing 1 1/2 digit calculations with exponential notation in my head. Like your evaporation problem. These days, though, I have a tendency to just raise my wrist and ask Siri, “How many inches to the Sun?”

erehweb 5y ago

While you certainly can calculate everything easily on a calculator, I think there's a value to being able to do your own arithmetic easily, in that this transfers over to good estimation skills and having a sense for when you typed the wrong thing into the calculator. Not something I have a proof of, though.

BeFlatXIII 5y ago
My teachers used to call that intuition "number sense".

kragen 5y ago

I did long division on paper yesterday, to convert swimming-pool evaporation rates given as millimeters per day to nanometers per second. Probably a skill I use every week or two. It's true that I could do it faster with a calculator. Perhaps a more practical example was that the day before yesterday my father told me that the recent collapse of an ice shelf off Antarctica was likely to raise sea levels by 27 inches in the next three to five years by debuttressing [what turned out to be] the Thwaites Glacier, so possibly the seaside camping spot he was enjoying that day would be under a foot of water in a few years. I immediately protested that this could not be correct; he must have misunderstood the research, because it was the wrong order of magnitude for such a short time period. And in fact it was the wrong order of magnitude, and the article he had read was deliberately sensationalized by juxtaposing sea-level rises that might occur over the next 80 years with events that will happen over the next three to five years. So his campsite will be fine. Didn't need mental long division for that, though.

wrycoder 5y ago
I’m terrible at arithmetic, but one very useful skill I have (probably left over from my slide rule days) is doing 1 1/2 digit calculations with exponential notation in my head. Like your evaporation problem. These days, though, I have a tendency to just raise my wrist and ask Siri, “How many inches to the Sun?”