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The panzer has spoken
(sh.itjust.works)
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this post was submitted on 09 Nov 2023
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They probably did, just not explicitly:
You could write (6*1/100)*50 = 6*(50*1/100)
It only uses the commutative property of multiplication and the fact that % is another way of writing 1/100.
Maybe also worth remembering that "x% of y" is just x/100*y
I'm confused again.
The word percent is exactly that per cent, which basically means parts of hundred. E.g. 10% are 10 of 100, or 60% are 60 of 100. You can also write this mathematically as 60/100 or 60÷100, which is 0.6.
Now in general: x% are x parts of 100 or x/100 or x÷100. If you want to calculate x% of y you just multiply it: y × x% = y × x ÷ 100.
This is one of those "maths is magical" moments, I guess.
Mathemagics.
I'm sorry but you have the big dumb
It's okay, not everyone learns through the explicit formulas. If the reversable idea is good enough for you, then that's great!
By what part?
I totally remember being taught this. It's just way easier to break down percentages in terms of the nearest 1% or 10% times the number in the percent times the number you're taking the percentage of. You don't have to do the math for the 1 or 10 percentage as long as you remember that a 10% means move the decimal left once and 1% means move the decimal left twice. The rest is just basic multiplication.
40% of 59 = 10% of 59 times 4.
So...
4x59=236
or
(4x50=200) + (4x9=36)= 236
10% means move the decimal left once,
Therefore 40% of 59 is 23.6
With that you can easily do more complex percentages mentally like...
62% of 35 = 10% of 35 times 6 plus 1% of 35 times 2.
35x6=180+30=210 at 10% so 21
plus
35x2=60+10=70 at 1% so 0.7
Therefore 62% of 35 = 21.7
While I get your sentiment, I'm always baffled how people fail to just memorize some basic formulas/equations and then just to plug and play:
1÷kⁿ = k⁻ⁿ
% = 1÷100 = 10⁻²
k×10ⁿ equals k with its floating point shifted by n to the right for positive n, or to the left for negative n
That's really all one needs to know for the "problem" at hand. For your concrete example of "40% of 59" that would just be
59×40×10⁻²
Just solve that whatever way is easiest. I don't get why people get panic-stricken when they see the % sign.