2 ms·

And then you get “why isn’t 3 × ⅓ equal to 1?” and similar questions. “Use rationals” would only postpone the issue to “Why isn’t (√2)² equal to 2?” and similar

• dylan604 4y ago
  > I would think that, nowadays, every child would learn that calculators do not always produce exact answers almost in kindergarten. such a strange comment to make. the number of people that would ever bump into this situation is so small. like the difference of .1 + .2 = .3 and .30000000000000004 i just used my iPhone to do (√2)² and it displayed 2 as the result. same for 3 x 1/3 to receive an answer of 1. i can only assume that the default android calculator app would behave the same. between those 2 apps, we've probably covered the default calculator for the majority of people. gotta break out of the HN is the world shell, and realize the majority of people do not suffer the same issues you might deal with on a daily basis.
• int_19h 4y ago
  Yes, children do learn that. But on the calculator, they're inputting numbers in decimal, and it's decimal internally. In programming, we input numbers in decimal, and even write them that way in source code, but the actual math is all binary - thus, there's a disconnect between the common sense expectation of what (0.1 + 0.2) ought to do, and what it actually does. Someone coming from a calculator would not expect that to be unequal to 0.3, unlike the situation with square roots.