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41 votes

Why are calculators not allowed in post-secondary exams?

As a professor/teacher I have some insight. You just answered your own question: "my level of math right now is not basic. So, like many, I tend to forget the basics of math, like adding fractions, ...
BobaFret's user avatar
  • 836
24 votes

Why are calculators not allowed in post-secondary exams?

In addition to @BobaFret's answer I'd like like to point out following: You said: Before you downvote this question, I actually want an answer to this. Is the calculator going to give me my ...
flawr's user avatar
  • 409
22 votes

What are some simple problems that calculators get wrong?

The first sentence of the question is "A frequent issue with students is their uncritical over-reliance on computation devices," hence my answer is in the spirit of presenting something ...
Xander Henderson's user avatar
  • 8,205
21 votes

Is it a bad idea to offer variants of a final exam based on the type of allowed calculators?

Let's start by saying that I strongly advice against such a dual-exam. Even if you and everyone involved in the planning think it is fair, students might think differently. In this way, you open up ...
Dirk's user avatar
  • 1,308
18 votes

Why are calculators not allowed in post-secondary exams?

One thing that really freaks me out about students on this site is an apparent inability, at least an unwillingness, to draw ordinary graphs on graph paper, maybe $y = x^3 - 3 x + 2$ or the like. If I ...
Will Jagy's user avatar
  • 415
14 votes

What are some simple problems that calculators get wrong?

Evaluate $L=\lim\limits_{x\to 0^+}(\sin x)(\ln x)^{100}$. Letting $f(x)=(\sin x)(\ln x)^{100}$, students might use their calculators to find that: $f(0.1)\approx 1.66\times 10^{35}$ $f(0.01)\approx 2....
Dan's user avatar
  • 991
14 votes

What are some simple problems that calculators get wrong?

The last time I taught introductory numerical analysis, my first slide was this print from excel: If you want another example: These calculations are clearly easy and wrong, as required. Remark 1: ...
Pedro's user avatar
  • 1,742
12 votes

Why are calculators not allowed in post-secondary exams?

I very much agree with already posted great answers (I do share most of the same opinions), but I'd like to add something else. Talking about math instruction we're not talking about math only — ...
zipirovich's user avatar
11 votes

What are some simple problems that calculators get wrong?

The easiest example off the top of my head is evaluating $(9^n)^{1/n}$ for a ridiculously large value of $n,$ large enough to have the calculator throw an overflow error. Something like $(9^{9^9})^{(1/...
Justin Skycak's user avatar
10 votes

Loaning students calculators during exams

To summarize what I arrived at, based on the top answer on my prior parallel question on SE Academia, OP's #2 is the way to go -- keep a small supply of calculators on hand, but assess a usage penalty ...
Daniel R. Collins's user avatar
10 votes

A study comparing effects of calculator usage on later math skills?

Studies such as Suydam (1979) indicate that there is not an adverse effect. However, most of the cited studies on the effects go back to the late 70's or early 80's. Anecdotally, as a high school ...
J. Plencner's user avatar
9 votes

Is it a bad idea to offer variants of a final exam based on the type of allowed calculators?

I think this is a bad idea, because it invites students to try to game the system: those who own a fancy calculator suddenly have to decide if they’re better off using it and taking an exam they think ...
Henry Towsner's user avatar
7 votes

What are some simple problems that calculators get wrong?

The easiest of all:$$\frac{1}{3} \cdot 3$$ :-) You can also go for large squares, something like: $$\frac{123456789^2 - 123456788^2}{123456789 + 123456788}$$ => for a human, this is just $\frac{a^2-...
Dominique's user avatar
  • 1,947
7 votes

Rational Powers of Negative Numbers on Basic Calculators

Answer: The calculators are fine, it is the question's premise "$(-8)^{2/3} = 4$" that needs to be fixed. Now this was a bit polemic, of course. Here's a more detailed description of what I ...
Jochen Glueck's user avatar
7 votes

What are some simple problems that calculators get wrong?

Ask a TI-89 to evaluate $\sin(n \pi)$ for different integers $n$, and you'll start out fine (when $n = 0, 1, 2, 3$), but starting with $n = 4$, you'll get values like $-2 E -13$. Or there's $8^{8^8}$ ...
Nick C's user avatar
  • 9,506
7 votes

What are some simple problems that calculators get wrong?

In a rather different vein, calculators can be correct in a numerical sense but miss an optimal solution method. In this answer two such cases are described, and I refer the reader to the above link ...
Oscar Lanzi's user avatar
6 votes

If a computer could be programmed to do a math test, then should those tests be changed?

No. There is a sort of magical thinking implicit here that something needs to stay, be different between computers and people. At the end of the day, we are "meat" computers. And the ...
guest's user avatar
  • 85
6 votes

What are some simple problems that calculators get wrong?

Occasionally I ask my students true-false questions of the following form: T/F? $1/3 = 0.333333333$ T/F? $\pi = 3.141592654$ They usually get these right as a group, but I think it's good to check ...
Daniel R. Collins's user avatar
6 votes

What are some simple problems that calculators get wrong?

Combinatorics might be a good place to look. A very basic example: given 200 items, how many ways are there to pick 1 item? Using the permutation formula involves calculating $200!/199!$, which not ...
BenM's user avatar
  • 177
5 votes

What are some simple problems that calculators get wrong?

Many cheap calculators ignore operator precedence. Type 1+2*3 on a good one and you'll get 7, do it on a cheap one and you get <...
Guntram Blohm's user avatar
5 votes

What are some simple problems that calculators get wrong?

Computers are quite bad at drawing curves with self-intersections. Examples below are made with Maple 13 (a quite dated version). The graph of $x^2+y^2=3xy$ looks particularly strange. We can get a ...
Taladris's user avatar
  • 1,491
4 votes

Why are calculators not allowed in post-secondary exams?

When I taught, we permitted students to have a symbolic calculator at all times. The implication for students of this is that the questions in the exam take this fact into account. When such a ...
MasB's user avatar
  • 767
4 votes

Loaning students calculators during exams

My intuition is that further penalizing already disengaged students will likely lead them to become even less engaged. It also sounds like some of these students might not know how to use scientific ...
TomKern's user avatar
  • 4,357
4 votes

What are some simple problems that calculators get wrong?

Some scientific calculators will round certain rational numbers to rational multiples of pi. For example, $\frac{11^6}{13} \approx \frac{156158413}{3600} \cdot \pi$. They may be assuming that the user ...
justforplaylists's user avatar
4 votes

What are some simple problems that calculators get wrong?

Here is a simple example. $ \def\lfrac#1#2{{\large\frac{#1}{#2}}} $   $\color{green}{\Big( 99 · \big( 100·\sum_{k=0}^{10} (-\lfrac1{99})^k-99 \big)^\lfrac1{10} - 1 \Big)^\lfrac1{9} = 0}$. Windows Calc ...
user21820's user avatar
  • 2,578
4 votes

What are some simple problems that calculators get wrong?

Continuing in the vein of "The calculator is right, but the interpretation by the user is wrong" I add a class of problems of the form $$\lim_{x \to \infty} \frac{p(\log(x))}{q(\log(x))}$$ ...
Opal E's user avatar
  • 4,044
3 votes

Loaning students calculators during exams

Allow the students to use Desmos Test Mode. The app allows students to lock a phone or other android/iOS device in single-app mode and use the Desmos graphing calculator that we know and love in an ...
Chris Cunningham's user avatar
3 votes

Best Free Direction Field Plotter?

I found a good example on Desmos: https://www.desmos.com/calculator/jkjgxemmkj And another on Geogebra: https://www.geogebra.org/m/W7dAdgqc
TomKern's user avatar
  • 4,357

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