I’ve used it to check how long I would need to save to reach a certain amount of savings considering my current spending/saving habits
I constantly use algebra/calc and graph data for my stem job. Everyone should have a similar base of knowledge. I don’t complain that I learned about the Mongolian empire or read Of Mice and Men.
Unfortunately, the people thinking they don’t need to know stuff are also the people “doing their own research” on vaccines and such.
Learning stuff doesn’t just impart knowledge, it rounds out your understanding of what you don’t know and where you should yield to expertice which is arguably equally as important as knowing stuff.
In this house,
𝑦 = −|𝑚𝑥| − |𝑏|.
We’re outta Absolut, sorry.
I used math to see if I could scale my 3d print model and see if it could fit in my print bed diagnolly instead of laid horizontally and vertically. My math was wrong, I thought I could do it but I missed some numbers.
I use calipers and math to figure out how much filament is left on a spool.
For example, think of the filament as one solid ring of plastic. My example spool is 60mm wide, the inner radius (of the filament, not the spool) is 28mm, and the outer radius is 40mm. Subtract the volume of the empty cylinder in the center from the solid cylinder of PLA, then multiply by 0.7 to account for packing density, and boom, you have a volume of filament that’s accurate to within a few percent. Convert that volume into cubic centimeters, multiply by 1.24, and you have a weight. This estimate gives my sample spool around 133 grams of filament.
For a quicker, less accurate method, think of the filament as a collection of individual circles wound around the spool. My example spool is 60mm wide, so that’s around 34 strands of filament, and the filament is stacked 12mm deep, so that’s around 6 strands of filament (it’s safest to round down). 34x6=204, so the filament is wound around the spool 204 times.
The average radius of one circle around the spool is probably 34mm (right in between the inner and outer diameters), so good ol 2πr gives us an average circumference of 213mm. 213mm×204 windings is around 43,500mm of filament, or 43 meters. Multiply by 3 grams (roughly the weight of 1 meter of filament). This estimate gives my sample spool around 129 grams of filament.
It sounds very involved, but once you get the hang of it it’s very intuitive. You just have to know that
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a circle’s circumference is 2π times the radius, or π times the diameter
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filament weighs about 3 grams per meter of length
Because I am the turboest of nerds I have made this a spreadsheet as well. Can’t actually share it for privacy reasons, but it fits within a 4x5 set of cells if anyone wants to copy it. You don’t even need to know what the math is doing, just copy the green highlighted functions into the cells verbatim and it should work like a charm. Just remember you’re using radii, not diameters
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“Another day has passed and I still haven’t used the notion that the height of something on a slope is equal to the horizontal distance from the start of the slope times the steepness of the slope plus the initial height of the slope off the ground.” I swear people treat math as something you explicitly need to sit down and write the equations for to get any use out of instead of just, like, them being useful to make you a more logical, well-rounded thinker. It’s like thinking the sole point of reading Of Mice and Men in 8th grade is so that you can randomly recite quotes from it years later.
I don’t remember very much of “Of Mice and Men”, and I don’t remember very much of the math I learned in school either. I’m not mad about having learned/read that stuff, but I also don’t feel bad about not remembering/using it since.
I went to a private high school in the US and graduated in 06, just to set the scene.
Animal Farm was on the reading list sophomore year, and you were tested on it strictly on the plot. What happened. Who did what. That’s it.
The class as a whole learned more about cheating than anything, because the teacher used the same tests for his whole career. They were typed on a typwriter, you just wrote your answers on your own paper and turned them both in. He was a good basketball coach from what I understand though, so… yeah.
that’s how it’s taught. learning to reason about problems is secondary to “just do the numbers”. you’re not graded on understanding.
I guess that greatly depends on your teacher. However, I will say that “doing the numbers” and understanding are pretty strongly correlated in math. BTW the same goes for English literature where reading more books greatly increases your understanding.
it’s a different kind of understanding though. also, vocabulary in school is always presented in context, while mathematics usually isn’t, save for contrived examples, because you can’t gradually introduce stuff the same as with language.
like, i never got an intuition for division. i have to brute-force it every time. during school i would ask for help and nobody else seemed to get it either.
Edit:
what i wanted to say wasn’t entirely clear, so let’s try again:
doing the numbers is only useful when you are working towards understanding. at least when i was in school, after an intro to multiplication, the table for e.g. 7 was presented “without comment”: we were to fill it in while timed, and if we did it quickly enough we were considered to have “learned” it, and got to advance to 8.
I think your example with the multiplication tables is a great one. It is important for students to have a understanding of what multiplication is both as a building block of more complex math, and because multiplication is one of the most practical skills we learn in school. Having said that, rote learning of multiplication tables is also a useful skill. By learning the multiplication tables you free up cognitive resources when learning something more complex.
i don’t know about that, i would prefer to build an intuition. i know people who simply have the entire thing memorized and “look up” the answer when prompted. which of course completely breaks down if you introduce an operand higher than 12.
You need both. Take 1718. Your understanding of multiplication should tell you that this equals 1010+107+108+8*7. Now your rote learning will allow you to calculate this quickly as 100+70+80+56=306.
you’ll need to escape the asterisks:
\*and no, my rote learning has not prepared me for that. nothing like that was ever presented to me. i went from multiplication tables to factorisation and never mentally connected the two. as a result i can’t do factorisation in my head at all, despite doing 80% of a master’s in engineering.
Seeming useless math can be applied if you look for opportunities.
When I attended military training for sergeant rank, there was a land navigation part. Plot the grid coordinates on a map, use a protractor to figure out the angles, which you then aim the compass towards and count paces to find the points out in the woods. I realized these made triangles and said fuck a protractor. I used trigonometry instead. Figured out the lengths of the sides of the triangles from the grid coordinates, then used those lengths and tangent to figure out the compass angle and distance. The instructors had no clue what I was doing. Took first place in that course because the other person I was tied with only found 3 out of 4 points in his two tries at landnav.
The best math skill for everyday life has to be dimensional analysis, though. Want to figure out how expensive it is to drive per hour? Well, you’ve got miles/hour, dollars/gallon, and miles/gallon. This can get you to dollars/hour by just canceling out the units. (I don’t have a paper to write things down but I think this is correct)
dollars/gallon X gallons/mile X miles/hour = dollars/hour
You can use dimensional analysis to convert all sorts of things. It’s awesome.
Yeah I know it’s the shitpost community but math is pretty cool.
Tangentially related, you can also combine a basic knowledge of math with a basic knowledge of spreadsheets to make people think you’re the second coming of Einstein
I shat this out in 5 minutes. All the white cells are user editable, and the blue cell calculates automatically. I could make it estimate annual gas costs by letting you adjust monthly mileage instead of speed and tweaking the math a bit. The average person would sooner close the application than try and make an interactive spreadsheet
Edit: I made the annual price one. You can either use monthly mileage for a good estimate, or distance to work for a very rough estimate (it multiplies the distance by 2x260 (2 to account for round trip, 260 because there are 52 weeks in a year and every week has 5 work days))
Of course it doesn’t account for non-work driving, but it also doesn’t account for holidays, so maybe it evens out
For my turbonerds out there, I’m not sharing the sheet itself because my name is on it, but here’s the behind-the-scenes
or the Planck energy drops.
I have a funny feeling that if that one happens, it stops being anybody’s problem
You can use a discipline that is named “measurement of the earth” to…measure earth? Fascinating!
I teach college chemistry, and half the time it’s to STEM majors that see the obvious applications, but the other half the time, my students are going into nursing or other “STEM-adjacent” fields and I try and try to get them to see that the applications are there, if they just look, but many of them never do.
I used the Pythagorean theorem and trigonometry to score an ~800 m headshot in Arma 3. It was a lot of grid spaces away. Pythagorean theorem to get the hypotenuse, then trig to get the vertical offset.
Felt like a math sniper badass when I hit the shot the first time.
NEEERDDDDD
Its either
ax+bormx+n
Pick one you lunatics…
We use Mx + C
C as in constant
y=kx+mWe were taught mx+b and ß0 + ß1x
I use it regularly
:•(
I tried to use it to see if I could see fireworks from my house once. I spent an hour or two before I realized it was actually a trigonometry problem and just had to figure out the angles.
The only other time was when I made a chart for a subreddit to show their average growth rate. I made them some art and a discord, and it was really cool to see the community flourish.
I find myself using parabolas a lot more often.
