If “close enough” works, then it’s nice to have the skill. Having the skill requires occasionally using it.
Where accuracy is important, since we almost always have a calculator with us now, that’s a no-brainer.
Maybe more to the point, though, understanding how percentages work is wise. It’s one of the few arithmetic topics that we encounter regularly in life.
In this case, 23% of 53 and 53% of 23 each have their own little trick, depending whether you’d rather overestimate a little with 1/4 of 52 or underestimate a little with half of 24. I find it handy to be able to think that way, especially for example when trying to get out of a taxi and paying cash.
Where accuracy is important, since we almost always have a calculator with us now, that’s a no-brainer.
Unfortunately most calculator apps were written by no-brainers who didn’t check they had their Maths correct. If you need accuracy then get a name brand like Sharp or Casio.
23% of 53
53% of 23, next question
Pretty close to 1/4 of 52, so like 13-ish, but maybe closer to 12.
(13 + 0.25 - 0.53 - 0.53, really. If I had to, I might be able to keep that in my head.)
.5*23=11.5
0.01*23=0.23
3*0.23=0.69
11.5+0.69=12.19
May as well just get out the calculator app to make sure. My point with those numbers is to just use a calculator. Why 2nd guess anything?
Calculator apps get order of operations questions wrong because of programmers who were too lazy to check they had their Maths correct
My point is avoid calculator apps like the plague. Use name brands like Sharp or Casio.
Guess what the programmer of your calculator app did 😂
If “close enough” works, then it’s nice to have the skill. Having the skill requires occasionally using it.
Where accuracy is important, since we almost always have a calculator with us now, that’s a no-brainer.
Maybe more to the point, though, understanding how percentages work is wise. It’s one of the few arithmetic topics that we encounter regularly in life.
In this case, 23% of 53 and 53% of 23 each have their own little trick, depending whether you’d rather overestimate a little with 1/4 of 52 or underestimate a little with half of 24. I find it handy to be able to think that way, especially for example when trying to get out of a taxi and paying cash.
Unfortunately most calculator apps were written by no-brainers who didn’t check they had their Maths correct. If you need accuracy then get a name brand like Sharp or Casio.
Babagedegaga. Ba.