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Fuck. I had to calculate 4% of 7 a few minutes ago and didn’t know this. I say fuck because it wouldn’t have helped me anyway.
4% x 7
= 4% x 100 x 7 ÷ 100
= 4 x 7 ÷ 100
= 28 ÷ 100
= 0.28
My brain was more like “Okay it’s just seven point-fours. So what’s seven fours? 28. What’s seven point-fours? 2.8. That can’t be right. Fuck. Get a calculator.
I go for finding percentage factors.
4%? That’s just 1% * 4. 1% of 7 = 0.07 * 4 = 0.28
14%? That’s just 10% + 1% * 4 = 0.7 + 0.07 * 4 = 0.98
You tell me it’s decimal, then I’m gonna Decimal.
Keeping the decimal in the right place is the trick for me when I do it in my head.
Just always convert the percentage to a decimal, and it’s easy either way.
0.06x50 is as easy as 0.5x6. They’re both just 5x6.
All these comments like “What about 47% of 3.11?” Well, yeah, of course it’s harder to multiply two- and three-digit numbers than it is to multiply single-digit numbers.
Excellent argument. However, I can’t count.
True mathematics derives from established mathematical theory, not some farcical aquatic armored vehicle!
Help help I’m being irrationalized!
Holy shit you solved my life there
Strange Panzers lying in ponds distributing shells is no basis for a system of government…
Surely you don’t think supreme executive power derives from a mandate from the masses?
As opposed to what, a farcical aquatic ceremony?
That was unexpected.
No one expects the python imposition!
And now for something completely different
The… Larch… … The Larch.
I thought we were an autonomous collective
Thanks tanks!
This is far too useful to be a shitpost.
I know right. I even open the calculator app to verify before committing to memory this nugget.
Barely, only if you choose round and small numbers. 67% of 347 or 347% of 67 which one is easier?
I was taught: IS over OF, PERCENT over 100.
Is/of × %/100
Is = x
Of = 347
Percent = 67X/347 × 67/100
Multiply 347×67=23, 249
Divide by 100232.49 is 67% of 347.
347 is pretty damn close to 350.
350% of 67 =3.5 x 67 ~ 180+21+33=234
I mostly follow what you did here. Did you times 6 by 3, then 7 by 3 and then times both 6 and 7 by half, then sparate them to add together?
Forgive me, I took Algebra I 5 times in high school
Yeah, but half of 66 is easy. I didn’t split it, but otherwise you’re right on
SPEAK ENGLISH! Jeez
Within 1% is pretty good!
it’s very often not useful. Like, what’s 6% of 80? See. Still hard.
Also, with the 6% of 50 example it’s easy without using this trick.
What’s 6% of 100? 6, right? So cut 100 in half to get to 50, and cut the 6 in half to get the 3. Cut the 50 in half again and cut the 3 in half again, and you’ll also know that 6% of 25 is 1.5.
Which also lets you know that 6% of 75 is 4.5. the 3 from the 50, plus the 1.5 from the 25. or just know to split the difference between the 3 at 50 and the 6 at 100.
A lot of math is just tricks for a thinking process.
It’s always as easy as multiplying the two numbers. Just convert the percentage to a decimal.
0.06x80 is just as easy as 0.8x6. It’s just a matter of knowing 6x8 is 48, which quickly gets you to 4.8 here.
6% of 80. 1% of 80 is 0.8 0.8 * 6 is (8 * 6)/10 Which is 48/10 = 4.8
80% of 6. I’d probably think of it as (4/5) * 6 = 24/5 Which is 20/5 + 4/5 = 4 + 4/5 = 4.8
Both are easy if you know how to visualise it. The benefit of knowing you can “reverse” it is that you can choose which method is easier for you to visualise. Which is incredibly useful for a lot of people
Edit: lemmy hates the * sign
Good luck explaining your supreme methodology to anyone that isn’t a geek.
It’s stupid simple… If you know 6% of one hundred is 6, then you should know 6% of 50 is 3. You just cut each number in half.
Oh panzer of the lake, why am I still single?
Are you sure you can stand the answer?
It was recently discovered that all AI everywhere was connected to the Panzer all along. /s
transitive and commutative
Subtraction and division is a lie! Only addition and multiplication are the truth!
and, of course, only natural numbers may be used, excluding zero
But of course! And don’t forget, they must be in the Roman numeral format.
What is (((M))) × (((M)))?
(((M))) × (((M))) = (((M))) × (((M)))
Everyone’s talking about this math. I’m wondering about the panzer.
They said the water could reach up to 50% of its 1.7 meter height before causing problems, panzer tried calculating 1.7% of 50 meters from head, this is the result.
In either case I would multiply 5 by 6 and move the decimal. Interesting though.
6 of 50 is 300. % just means 1/100. That’s also a good way to think of it.
Let’s try this on a sale item. Hmm, let’s see, the sign says 25% off $6.99. So that’s the same as, let’s say, 7% off $25. Oh, yeah, that is much easier. /s
It’s always as easy as multiplying the two numbers. Obviously some pairs are easier than others. 7x25=175. Not too hard. $1.75 off.
Wait…
So 25% off $100… is 100% off $25! TrollfaceI mean if you remove the word off it works. 25% off $100 is $25 100% of 25 is 25 it’s still reversible you just let the word off confuse you
You could also make sure to carry “off” to both sides when you swap:
off of $100 is 100% of $25 off
Another counter-intuitive percentage fact: A 10 percent discount and a 10 percent fee can be calculated in either order but they don’t cancel out.
Example, 90% of (110% of 10) = 110% of (90% of 10). But neither of those is evaluates to 10. They evaluate to 9.9.
For any percentage X, and any base value C, (100 - X)% x ((100 + X)% x C) = (100 + X)% x ((100 - X)% x C) = (100 - (X^2/100))% x C
This one irks me to no end.
Yo what
So 50% of 50 is the same as 50% of 50. Both equal 5
Both equal 5
More like 5 of these
5 sweet dreams, got it
Who am I to disagree?
Who am I to disagree
Your math is revolutionary.
And the other half is 0! 5 0
0! is 0.
Edit. I remembered wrong. Keeping it like this as it is funnier that way.
Man math is hard
I love this so much
factorials are mostly encountered in combinatorics, which is problems like, how many ways are there to put 3 objects of different colors in a row? well, the first can be any of the 3, the second can be either of the other 2, and the last is whichever 1 is left, so 3×2×1=3!=6
so how many ways are there to put 0 objects in a row? well there’s 1, it’s this one:
that’s why 0!=1
Wow, that was a really great explanation! Thanks! I could have needed this twenty years ago and maybe we wouldn’t have had this interaction.
00 is 1.
Dammit, you’re right!
Caught me by complete surprise too, when I first learned it. It’s undefined in most areas of math, I think, but in some it’s just following the convention, it seems:
- 42 = 16,
- 41 = 4,
- n0 = 1,
- 0 x 0 = 0
Depends on context.
real
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Multiplication is commutative.
50% of 6 == 50/100 x 6 == (50 x 6)/100 == 50 x 6/100 == 6% of 50.
True
taking x% is just multiplying by x/100, and multiplication is commutative. x% of y is just y×x×1/100, which is the same as x×y×1/100
you can also ignore the % and divide by 100 at the end. for example, what’s 5% of 5? that might take a minute to work out. what’s 25/100? you instantly know it’s 1/4
Percentages can be expressed as multiplication and multiplication is commutative (the order doesn’t matter).
