What You Need To Pass This Class


It’s near the end of the (US) college fall semester. So it’s a good time to point out again that it is possible to work out exactly what you need on the final exam to get whatever grade you want in the course. What it’s not possible to do is study just exactly enough to get that grade, mind you. I suppose it can give you some idea where a good study session can most make a difference, but really, what you need is to study routinely and to get enough sleep.

But if you are just trying to get a rough idea of what you need, here’s a table with common cases, of final exam weight and to-date averages. If that chart misses what your particular case needs (and, remember, there is no point to looking to great precision) here’s the formula to work out specifically your problem.

And, as long as I have this open, let me share an episode of The Vic and SadeCast, about the renowned and strange 15-minute old-time-radio serial comedy Vic and Sade. Most episodes of the serial were two or three people talking past one another. The show may not be to your tastes, but if it is, it’s very much to your taste. This episode of the podcast features an October 1941 show aptly titled It’s Algebra, Uncle Fletcher.

What You Need To Pass This Class. Also: It’s Algebra, Uncle Fletcher


The end of the (US) semester snuck up on me but, in my defense, I’m not teaching this semester. If you know someone who needs me to teach, please leave me a note. But as a service for people who are just trying to figure out exactly how much studying they need to do for their finals, knock it off. You’re not playing a video game. It’s not like you can figure out how much effort it takes to get an 83.5 on the final and then put the rest of your energy into your major’s classes.

But it’s a question people ask, and keep asking, so here’s my answers. This essay describes exactly how to figure out what you need, given whatever grade you have and whatever extra credit you have and whatever the weighting of the final exam is and all that. That might be more mechanism than you need. If you’re content with an approximate answer, here’s some tables for common finals weightings, and a selection of pre-final grades.

For those not interested in grade-grubbing, here’s some old-time radio. Vic and Sade was a longrunning 15-minute morning radio program written with exquisite care by Paul Rhymer. It’s not going to be to everyone’s taste. But if it is yours, it’s going to be really yours: a tiny cast of people talking not quite past one another while respecting the classic Greek unities. Part of the Overnightscape Underground is the Vic and Sadecast, which curates episodes of the show, particularly trying to explain the context of things gone by since 1940. This episode, from October 1941, is aptly titled “It’s Algebra, Uncle Fletcher”. Neither Vic nor Sade are in the episode, but their son Rush and Uncle Fletcher are. And they try to work through high school algebra problems. I’m tickled to hear Uncle Fletcher explaining mathematics homework. I hope you are too.

Reading the Comics, July 1, 2017: Deluge Edition, Part 2


Last week started off going like Gangbusters, a phrase I think that’s too old-fashioned for my father to say but that I’ve picked up because I like listening to old-time radio and, you know, Gangbusters really does get going like that. Give it a try sometime, if you’re open to that old-fashioned sort of narrative style and blatant FBI agitprop. You might want to turn the volume down a little before you do. It slowed down the second half of the week, which is mostly fine as I’d had other things taking up my time. Let me finish off last week and hope there’s a good set of comics to review for next Sunday and maybe Tuesday.

Ted Shearer’s Quincy for the 4th of May, 1978 was rerun the 28th of June. It’s got the form of your student-resisting-the-word-problem joke. And mixes in a bit of percentages which is all the excuse I need to include it here. That and how Shearer uses halftone screening. It’s also a useful reminder of how many of our economic problems could be solved quickly if poor people got more money.

Teacher explaining budgets: 'Quincy, does your granny have a budget?' Quincy: 'She sure does! 30% for rent, 30% for food, 30% for clothign, and 20% for the preacher, the doctor, lawyer, and undertaker!' 'That's 110%' 'That's our problem!'
Ted Shearer’s Quincy for the 4th of May, 1978 Not answered: wait, Quincy’s Granny has to make regular payments to the undertaker? Is ‘the preacher, the doctor, lawyer and undertaker’ some traditional phrasing that I’m too young and white and suburban to recognize or should I infer that Granny has a shocking and possibly illicit hobby?

Olivia Walch’s Imogen Quest for the 28th features Gottfried Leibniz — missing his birthday by three days, incidentally — and speaks of the priority dispute about the invention of calculus. I’m not sure there is much serious questioning anymore about Leibniz’s contributions to mathematics. I think they might be even more strongly appreciated these days than they ever used to be, as people learn more about his work in computing machines and the attempt to automate calculation.

Mark Anderson’s Andertoons for the 28th is our soothing, familiar Andertoons for this essay. I remember in learning about equivalent forms of fractions wondering why anyone cared about reducing them. If two things have the same meaning, why do we need to go further? There are a couple answers. One is that it’s easier on us to understand a quantity if it’s a shorter, more familiar form. \frac{3}{4} has a meaning that \frac{1131}{1508} just does not. And another is that we often want to know whether two things are equivalent, or close. Is \frac{1147}{1517} more or less than \frac{1131}{1508} ? Good luck eyeballing that.

And we learn, later on, that a lot of mathematics is about finding different ways to write the same thing. Each way has its uses. Sometimes a slightly more complicated way to write a thing makes proving something easier. There’s about two solids months of Real Analysis, for example, where you keep on writing that x_{n} - x_{m} \equiv x_{n} - x + x - x_{m} and this “adding zero” turns out to make proofs possible. Even easy.

Mark Tatulli’s Heart of the City remains on my watch-with-caution list as the Math Camp story continues. But the strip from the 28th tickles me with the idea of crossing mathematics camp with Pinocchio‘s Pleasure Island. I’m imagining something where Heart starts laughing at something and ends up turning into something from Donald Duck’s Mathmagic land.

Dave Blazek’s Loose Parts for the 28th is your traditional blackboard-full-of-symbols joke. I’m amused.

Tony Rubino and Gary Markstein’s Daddy’s Home for the 1st of July is your traditional “mathematics is something hard” joke. I have the feeling it’s a rerun, but I lack the emotional investment in whether it is a rerun to check. The joke’s comfortable and familiar as it is, anyway.

Algebra, Explained


It always feels odd to toss folks from my mathematics to my humor blog. I suppose it only sometimes seems on-point. Last week, though, I ran a series of essays about the old-time radio series Vic and Sade. One of them, happening to star neither Vic nor Sade, was all about Uncle Fletcher trying to explain algebra, or arithmetic, or something or other. The radio program won’t be to everyone’s tastes. It had a very dry style, closer in tone to a modern one-camera sitcom than anything where there’s a studio audience and easy-to-quote patter. And it does start with an interminable advertisement for sponsor Crisco. (It also includes a contest that adds to the announcement’s length. I assume we’ve missed the contest deadline.) But past the first three minutes and twenty seconds you get some fine mathematics exposition. I hope you enjoy.

And The $64 Question Was …


I ran across something interesting — I always do, but this was something I wasn’t looking for — in John Dunning’s On The Air: The Encyclopedia of Old-Time Radio, which is about exactly what it says. In the entry for the quiz show Take It Or Leave It, which, like the quiz shows it evolved into (The $64 Question and The $64,000 Question) asked questions worth amounts doubling all the way to $64. Says Dunning:

Researcher Edith Oliver tried to increase the difficulty with each step, but it was widely believed that the $32 question was the toughest. Perhaps that’s why 75 percent of contestants who got that far decided to go all the way, though only 20 percent of those won the $64.

I am a bit skeptical of those percentages, because they look too much to me like someone, probably for a press release, said something like “three out of four contestants go all the way” and it got turned into a percentage because of the hypnotic lure that decimal digits have on people. However, I can accept that the producers would have a pretty good idea how likely it was a contestant who won $32 would decide to go for the jackpot, rather than take the winnings and go safely home, since that’s information indispensable to making out the show’s budget. I’m a little surprised the final question might have a success rate of only one in five, but then, this is the program that launched the taunting cry “You’ll be sorrrreeeeee” into many cartoons that baffled kids born a generation after the show went off the air (December 1951, in the original incarnation).

It strikes me that topics like how many contestants go on for bigger prizes, and how many win, could be used to produce a series of word problems grounded in a plausible background, at least if the kids learning probability and statistics these days even remember Who Wants To Be A Millionaire is still technically running. (Check your local listings!) Sensible questions could include how likely it is any given contestant would go on to the million-dollar question, how many questions the average contestant answer successfully, and — if you include an estimate for how long the average question takes to answer — how many contestants and questions the show is going to need to fill a day or a week or a month’s time.