## Soft Post: Tools of the Trade.

### January 26, 2011

Before this post, I outlined another post which attempted to find the average price of being a mathematician — or, in other words, what does it cost to be able to get a BA in math, including tuition, tools, books, and so forth. A lot of my estimates were arbitrary, so I’ll post about a slightly different topic: **what tools do I use on a regular basis to do mathematics, and how much do they cost?**

This idea stemmed from an argument I had with one of my friends about how expensive it was to major in science verses how inexpensive it is to major in the humanities (her theory was that more lower-income people choose the humanities because it’s cheaper than doing science; I don’t have the data to back up any arguments on this, so I’ll resist debating any of you on this point). I wanted to see how much I’d have to pay if I needed to replace all of the tools I use frequently (say they all exploded in a math building fire of some sort; it’s been known to happen). In the comments, feel free to calculate your own total!

** **

**My pencil.**I’ve tried dozens of pencils and pens out throughout the years but the Alvin Draft-matic 0.5mm pencil is by far the best second only to the Pentel 0.5mm. I have one of the former (a whopping $13) and two of the latter (a more modest $8 for both together). With an extra thing of lead (around $6), the total for writing tools is:**$27**.**My eraser.**Yes, every pencil has an eraser, but not all erasers are created equally. I’ve found that the pentel’s and alvin’s erasers are too small and get rubbed out too quickly. The circular mechanical eraser is fine, but I’ve found that I can erase quickly and easily with the pentel tri-eraser which only set me back around**$6.**These things last for a while; I’ve been using the same one for about 4 months now — and they come in packs of two.**Paper.**I use standard unlined printer paper, and this is literally everywhere in the math department so it costs me nothing. I put my work manila envelopes which are also everywhere (I found mine in the recycling trash. They were clean, don’t worry). This costs me nothing.**Clipboard.**I use this with my paper. I have an A&W clipboard, because that’s all they sell here. It was**$4**.**Organizer.**I use a crappy little CVS accordian organizer to put all my papers in. I can’t find it online, but it was**$10.****Computer.**Because I am given a computer at school to use, I am not counting this. There are also computers to use in the library, and so forth.**Graphing.**I don’t use a graphing calculator on a regular basis, but when I need graphing done I go to wolfram alpha to do it. If that doesn’t work, I use mathgv which is this free graphing program that I’ve been using since the start of undergrad. If both of these fail me, then I turn to mathematica (see below). These things cost me nothing.**Computation.**I’m a student, which gives me mathematica for free. I also have a “free” version of mathematica on my laptop, which I use a fair amount — generally if I need a huge computation done, or a huge integral solved, or a more complicated graph output. This costs me**$0.****Formal writing.**For mathwork, I use TeX (as many of you do) which is, of course, free. I also LyX for non-math papers, which is also free and is built on latex. This costs me**$0.****Texts.**Unfortunately, I’m one of those students that loves having a physical copy of the book around. But, for now, there’s only six books I would consider absolutely necessary for me to have: Kolmogorov’s Real Analysis, Dummit + Foote’s Algebra, Munkres’ Topology, Hatcher’s Algebraic Topology, Lang’s Algebra, and Mac Lane’s Categories for a Working Mathematician. These books are the only ones I think that I use at least once a week every week. These would cost me approximately: $10 + $65 + $115 + $30 + $60 + $60 =**$340**.

All of this costs me a total of $387 dollars. If I didn’t want to count the books (I have online copies of each of these anyway) it would only cost me $47. If I replaced everything two times a year, this is only $94. That’s not all that bad.

according the irs, i can only deduct 250 dollars for “educator” expenses, but this is what i use on a daily basis.

write source teacher’s guide – 87 dollars

write source MUGS – 37 dollars

sharpie pens (pack of 4) – 9 dollars

manila folders, color coded and 3-tabbed – 37 dollars

copies of pertinent documents – 0 dollars

dry erase markers (pack of 4) – 15 dollars

paper organizer (5) – 55 dollars

hanging folders – 11 dollars

folder labels – 17 dollars

chapstick (essential in any job) – 4 dollars

bottled water – 15 dollars

computer with internet access – 1000 dollars

promethean board – 1500 dollars

projector – 1000 dollars

and i can’t think of anymore because i’m so sick. and lazy; i should be working.

Right, but that doesn’t account for opportunity costs. Learning mathematics costs a

lotof time.Yes; I think I’d started to write something similar to that and decided it was difficult to figure out that cost. For this post [it was a while ago, so I forget exactly what caused me to write this] I only investigated the *tools* I used.

It depends what your alternative is. But at a minimum you could say working 40 hrs/week at $8/hr = $16,000/year as a probably nonbinding lower bound.

Or maybe you could look at a given day and assume you could either tutor a lower level student (for $20?) or or work through some exercises of your own material. Assume tutoring the lower level student nets you some cash but you choose to take the proof as granted rather than convincing yourself/exploring more. Then you could derive the costs from a more granular basis.

Opportunity cost is a bit of a monster because we cannot quite say that a minimum wage job is the “worst” we can do — and, moreover, If someone is learning skills [in school or otherwise] this is an investment but is not easily able to be quantified. This is mainly why I steer clear of it here.