# Handing out $2 calculators for tests? In a store last weekend, I saw a simple solar-powered calculator for$2. It had four functions plus a square root key. I'm considering the possibility of buying 50 such calculators and handing them out for use during exams in my freshman calc course, as the only calculators allowed.

• No difficulties with determining whether a device is a calculator or a phone, is a graphing calculator, has internet or text-messaging, can do symbolic math, can store notes, ...

• In some cases it's sensible to check one's results on calc problems numerically. For instance, I give homework where they differentiate some function and then check themselves numerically by calculating a delta-y/delta x. It would be nice to allow them to use calculators on exams so that they could do the same thing.

• Prevents an arms race for students trying to use fancier calculators. Saves students money by eliminating a perceived incentive to buy an expensive calculator that actually has low added utility.

• A hassle to maintain the sack full of calculators, replace broken ones, etc.

• May mask incompetence in basic arithmetic skills.

• Problems would have to be carefully designed so that if a numerical check is required, it stays within the capabilities of the calculators (not so good for transcendentals).

• Any problem with a calculator (broken key, ...) becomes my fault.

Has anyone tried this? Is it a good idea?

• Somewhat related: I posted in an earlier thread about studies on (graphing) calculator use in Calculus classes. matheducators.stackexchange.com/a/998/262 – Benjamin Dickman Jun 25 '14 at 21:19
• I have not tried this, so I cannot really answer. But I think this is a great idea for certain courses and am definitely stealing it. – Brendan W. Sullivan Jun 25 '14 at 21:39
• I set my exams up to not require (or benefit) from calculator help. And I don't feel too cramped by this. Dunno, would be interested in how it turns out... – vonbrand Jun 25 '14 at 22:59
• It might be necessary to have a practice session with the calculators before exam day. A student who habitually uses a scientific or graphing calculator may be a bit confused when going back to a four-function calculator for the first time, especially with things like order of operations. – Will Orrick Jun 26 '14 at 2:27
• Those cheap calculators don't last long. You'd need to have extras on hand so that students could request to swap theirs out if it didn't seem to be working correctly during an exam. Could you instead put a specific \$5 basic calculator on the required texts/materials list for the course? \$5 is nothing in the textbook budget of an undergraduate, and they'll have it as a backup for future use. – PurpleVermont Jul 13 '14 at 23:25

I haven't tried this, but here are some comments and suggestions.

Although one might expect students to be able to do basic arithmetic (and thus not need calculators at all), if your exam involves numbers with many significant figures or with square roots, it would make sense to let them use a basic calculator (since you are teaching freshman calculus and not, say, grade school arithmetic).

Consider who will shoulder the expenses, that is, who will own the calculators. If you use school money to buy the calculators, you will be held accountable if they are lost, stolen, or damaged. If you sell the calculators to the students, this might be seen as an unethical practice, even if it is clear that you did not profit from the sales.

The following suggestions assume that either you or the school owns the calculators.

Assign each student a unique number, label the calculators with these numbers, and assign each calculator to the corresponding student. This will make it easy to identify who is responsible if the calculator is stolen or damaged. Make it clear from the start what the penalties are for these cases.

I think it would be better if you were the one to keep the calculators when they are not in use. If you let the students take the calculators home it becomes more difficult to hold them accountable for the calculators (for example, a student might claim someone else stole his/her calculator when in fact he/she was the one to steal it).

• If the calculator isn't turned back in, it is the student's fault. If it is stolen, misplaced, run over by a truck, whatever, is of no consecuence. – vonbrand Jun 26 '14 at 12:20

As of this academic year, for many courses, our students are restricted to a basic relatively-inexpensive scientific calculator during tests/exams. Students are required to buy such a calculator themselves, but we also keep a box of calculators owned by us handy for emergencies. A student can borrow a calculator for the duration of a test and then return it.

Part of the reason for the restriction was to level the playing field, as the occasional student was found using a calculator with advanced or unknown capabilities such as symbolic mathematics or a device running in a foreign language. Permitting a scientific calculator means that students do have access to transcendental functions.

• The problem is that even "basic scientific calculators" are today capable of storing large texts (they were used to cheat in my day, some 35 years back...) – vonbrand Jun 26 '14 at 12:23
• @vonbrand: We require a specific model of calculator that cannot store text, at least not to my knowledge. – J W Jun 26 '14 at 12:45
• One easy way to find a sufficiently basic calculator is to read recent rules from International Physics Olympiads. Around 15 years ago the approved one was the TI-30X. This year the approved one is HP10S+. – Willie Wong Jun 30 '14 at 13:35