Math Curmudgeon
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mathcurmudgeon.bsky.social
Math Curmudgeon
@mathcurmudgeon.bsky.social
650 followers 460 following 440 posts
~40 years teaching HS math, physics & computer science. #iteachmath
He/Him/Sir/Mr. M

Alaxandr
Combat Archer, Northern Army
SCA: Society for Creative Aachronism
"Þæs ofereode, þisses swa mæg."
"That passed; this too shall pass."
Posts Replies Media Videos
mathcurmudgeon.bsky.social
Simple Fahrenheit to Centigrade conversions on a calculator.

Life should be more simple.
#Calculators
#PEMDAS
#GEDMAS
5/9x(70-32)=21.111 5/9(70-32)=0.014619883
September 20, 2025 at 1:32 AM
mathcurmudgeon.bsky.social
Nerd-sniped myself this morning:

I found myself wondering if the hypotenuse of one of the triangles ever lined up *exactly* with the leg of another, and if so, which one?
May 17, 2025 at 5:07 PM
mathcurmudgeon.bsky.social
Things my students said today:
"A corner of your cheese landed on my chair." & Massive giggle fit. To her sister: "Take your earpod out of your ear, young lady." More giggles. Drops calc on own foot: "My foot. It's been attacked." Whole class loses it.
#mathstoday
#iteachmath
#YeahItsAlmostSummer
May 13, 2025 at 10:10 PM
Reposted by Math Curmudgeon
joshgondelman.bsky.social
I can't believe we have a Pope from Illinois. People from Chicago usually hate the Cardinals.
May 8, 2025 at 5:51 PM
mathcurmudgeon.bsky.social
Rational Functions, factoring review, operations with algebraic fractions ... all wrapped up into one set of problems, with code-breaking. It's like butttaaah.
#algebra2
#mathstoday
Rational Functions Cipher Puzzle v2 Simplify each expression; match to the answers on the other side. 1. (5x+15)/(x^2-x-20)*(2x-10)/(10x^2+50x+60) 2. 4/(x-5)-(4x+7)/((x+2)(x-5)) 3. (4x^3+12x^2)/(x^2+5x)÷(2x^4+10x^3+12x^2)/(x^3+5x^2-4x-20) 4. 3/(x+2)+1/(x+4) 5. 4/(3(x+4))-(x+2)/(x+4)(x+1) +2/(3(x+1)) 6. (x^4-x^2)/(x+5)*(x^2+3x-10)/(x^4-5x^2+4) Matching. A. 1/(x^2-3x-10) B. 2(x-2)/x C. 2(2x+7)/(x^2+6x+8) D. 1/(x^2+6x+8) E. x^2/(x+2) F. (x+2)/(x^2+5x+4) From the other side, list the answers to create the key to a Vigenére Cipher. Vigenére KEY: ___ ___ ___ ___ ___ ___ Use the coding / decoding tools at http://rumkin.com/tools/cipher to decode the following instructions. For each of the rational functions that follow, write in order (leaving off negative signs) AIOV AE KA IQQI; FHBPLI WO MGYXHRT CSH XSF TTX13 f(x)=(2(x-25)(x+24))/((x-2)(x+24)) f(x)=(21x-315)/(x+18) f(x)=(17x^2+340x-748)/(x^2-3x+2) f(x)=(16x-400)/(x+17) f(x)=(32(x-14)(x-8))/(2(x-8)(x+25)) f(x)=(6x^2+240x+2250)/(x^2+23x+120) f(x)=(24(x^2+4x-12))/(x^2+8x+12)
May 8, 2025 at 6:11 PM
mathcurmudgeon.bsky.social
#NewTeacherAdvice
Small whiteboards, cheap markers (~ $0.10 each) are well worth the math department investment.
view of classroom table with white boards, markers, and a rational functions simplification problem written on a white board.
May 5, 2025 at 9:17 PM
mathcurmudgeon.bsky.social
#MTBoS #Iteachmath It's time for the occasional reminder of the day in 2021 when I did a Google Image search for "Math Icons". I was looking for images to use on a website menu ... symbols, math class cartoons, and such. Here's a partial screenshot.
IYKYK
google image results for "math icons" Includes a picture of Sam.
April 9, 2025 at 1:51 PM
mathcurmudgeon.bsky.social
Something has changed about the decor in the White House but I just seem to put my finger on it … maybe there’s a bit more orange and gilt?
April 8, 2025 at 1:53 PM
mathcurmudgeon.bsky.social
If you’re going to criticize and/or ridicule the 86 yo president for typos, you should probably run spell check on your own article before publishing.

“allowed”
April 4, 2025 at 2:27 PM
mathcurmudgeon.bsky.social
And you kids said there was never going to be a use for negative numbers in the real world!
Adam Kitzinger tweet says that he now has negative four security clearances after Tulsi Gabbard posts that his clearance has been revoked again.
March 29, 2025 at 6:50 PM
mathcurmudgeon.bsky.social
Another update on a DESMOS file that shows transformations by highlighting points.

Any ideas for improvement?
#iteachmath #mathstoday
www.desmos.com/calculator/s...
ALG2 - Transformations Update
www.desmos.com
March 27, 2025 at 8:49 PM
mathcurmudgeon.bsky.social
If anyone is interested, here's a quick mock-up of how you can show points translating along with translating curves.
#Iteachmath #algebra #MathsToday
www.desmos.com/calculator/k...
ALG2 - Transformations Update
www.desmos.com
March 21, 2025 at 4:15 PM
mathcurmudgeon.bsky.social
Love this visual of the proof of the angle sum theorems in Precalculus. I do it every year and it never fails to amaze.
Horizontally:
Green=yellow-pink
cos(A+B) = cosAcosB-sinAsinB

Vertically:
Yellow = green + pink
sin(A+B) = sinAcosB + sinBcosA
#iteachmath
#MathsToday
Right triangle in a rectangle to show why the angle sum formulas in trigonometry work.
March 14, 2025 at 9:57 PM
mathcurmudgeon.bsky.social
Setting up for the German Tank problem ...
blog.mathmedic.com/post/bring-b...

Counting out and numbering popsicle sticks, la la la, and I end up with 88.

No, wait. The last two just snapped. It's only 86.
Bring Back the German Tanks
Josh Tabor discusses a revised version of the German Tank Problem - an excellent activity for introducing sampling distributions.
blog.mathmedic.com
March 13, 2025 at 5:05 PM
mathcurmudgeon.bsky.social
Hello, World.
Sorry, but this is who the USA is now. A lot of us voted for Harris, but enough people voted for nobody, or sat out, or voted for the iDJT. Half of our Government is fully behind the Orange One, and half of the country LOVES it. Apologies in advance for what we're about to do.
March 5, 2025 at 2:51 AM
mathcurmudgeon.bsky.social
Hey, @cnn.com
When you interview a fired govt worker, it’s fine to focus on that person and the impact on them, but you should also highlight what now isn’t getting done for USA.
Breaking News, Latest News and Videos | CNN
View the latest news and breaking news today for U.S., world, weather, entertainment, politics and health at CNN.com.
cnn.com
February 27, 2025 at 2:08 PM
mathcurmudgeon.bsky.social
In #mathstoday, the alg2s worked on The Problem.
The data in the following table list natural gas consumption ( in quadrillion BTU ) in the United States. Estimate the consumption in 1982, 2000, 2010, & 2016. Natural Gas Consumption Year: 1960 1970 1980 1990 1997 Consumption: 12.4 21.8 20.4 19.3 22.6 Source: US Department of Energy A. Enter the data into a table. Use two-digit years. With only the data appearing on your graph, estimate the numbers for 1983, 2000, 2010, and 2016. a. When you estimate, remember that this is real. Why would natural gas consumption change in the way you think it would? B. Find a polynomial function that models the data. a. Desmos, create a table. Enter the values. b. What order function does that data seem to be following? c. Create a regression. d. What is the equation that seems to match the data best? C. Graph the model and the data together. Take a screenshot. a. How good is the match between the model and the data? b. Use your model (equation) to estimate natural gas consumption in 1982. c. Can we feel confident about the 1982 estimate? Explain why or why not. D. Use your model (equation) to estimate the natural gas consumption in 2000, 2010 and 2016. a. Can we feel comfortable about these estimates? Explain why or why not. How good was your model? Imagine that the 2000, 2010, and 2016 numbers were dramatically different from your model … how different would they have needed to be to make you reconsider and choose a different model in Part B?
February 18, 2025 at 9:20 PM
mathcurmudgeon.bsky.social
Kerning is important
February 13, 2025 at 9:11 PM
mathcurmudgeon.bsky.social
In #MathsToday.
The box announces that Cologuard finds 92% of colon cancers. Later in the ad, we're told false positives can occur & this slide flashes on the screen.
If you receive a positive result, what are the chances that you do have colon cancer?
Cologuard advertisement. Banner says "In a clinical study, 13% of people without cancer received a positive result (false positive) and 8% of people with cancer received a negative result (false negative)
February 13, 2025 at 7:31 PM
mathcurmudgeon.bsky.social
This is true. 💯💯💯
#DoThis #MathMistakes #SheerTerror
#DontDeleteMyTiktok
February 12, 2025 at 10:05 PM
mathcurmudgeon.bsky.social
Too traumatizing?
Every time you do this: sin^(-1) x =1/sinx Elon Musk tweet: He's the worst, sorry.
February 11, 2025 at 10:55 PM
mathcurmudgeon.bsky.social
Which one is better, Bluesky?
Every time you do this: 2*3^2=36 The picture of an otter holding his (her?) paws out "to stop" it, saying "HOLD UP" Every time you do this: 2*3^2=36 The picture of an otter holding his (her?) paws out "to stop" it, saying "You need to paws and consider your sins"
February 11, 2025 at 10:36 PM
mathcurmudgeon.bsky.social
Last of the older set.
February 11, 2025 at 4:35 PM
mathcurmudgeon.bsky.social
Four more for today.
Disrespectful bear cub for adding fractions incorectly Disappointed puppy for misusing the distributive property. Evil raccoon enjoys your mistake with radicals (surds, if you're British) Math unicorn has its feelings hurt when you screw up your square root operations: r(4) + r(6) = r(10)
February 10, 2025 at 3:06 PM
mathcurmudgeon.bsky.social
What's up, Bluesky?
February 9, 2025 at 4:07 PM