Every time a teacher emphasizes formula triangles, a student loses a chance to understand math.
And I am persistently undermined when I try to teach the algebra. 🤬
I cannot get algebra buy-in from my student who's struggling ... struggling bc he can't read the language of maths ... BECAUSE he is being taught to value janky work-arounds with blind memorization instead of ANY ACTUAL UNDERSTANDING AAARRRRGGHGHHHHHHHH HULK SMASH
@RealityMinus3
I've had conversations about formula triangles with various students in different classes in recent weeks.
"Can't I just use the formula triangle, sir?"
"If you know what's going on and the formula triangle helps you to answer a question then fine, but I'm never going to teach you it that way because whilst they seem like a good shortcut they're _really_ unhelpful for understanding _why_ it works."
I did have one occasion when a kid was trying to rearrange an equation of the form a=b/c, and he was struggling. After a while his eyes lit up and he said "ohhhh, I can make a formula triangle to do it!"
While formula triangles are terrible, the fact he came at one from the opposite direction under his own steam and managed to make a generalisation out of something that's usually only ever "taught" in very specific situations was actually pretty useful for him. This is a rare exception, though, in my experience.
@TeaKayB AAAAARRRRRRRRRRGGGGGGGGGHHHHHHHHHHHH.
That poor kid!! He's clearly got capacity and intellect, and he's being smashed on the rocks of You Must Be Thick And Can't Do Maths Here's A Formula Triangle. That poor lad!! Nobody should have to reinvent the gods damned wheel like that.
I don't understand the purpose of formula triangles. They are entirely misleading, IMO! Admittedly, it's the way we were taught in early physics class at Russian middle school, but it never came back to me... because I was lucky enough to see beyond the diagrams, I suppose.
I kinda enjoy the physics that were taught in college, though. I learned how to make unit conversions in giant formulas and they still hit home more than these pesky triangles.
@vintprox Oh, gods, yes! Outside of school, I learned how to use equivalent fractions to do unit conversion.
3km/1 * 5mi/8km .... etc Cancel the units. SO HELPFUL! I never have to "reason" my way through whether I need to multiply or divide or any stupid faff. (for checking my answer makes sense, sure, but not for the calculation)
RealityMinus3 & Zeke Rat
Tommaths (he/him)
Antonio Patriarca
Simon Koch 
Vint Prox