I nearly reposted a Facebook article that had one of those pixelated JPEGs (if you’re going to use an image, at least use a PNG) with some text on it which managed to solicit thousands of responses. The reason I wanted to repost it was not because I thought it was clever or witty or fun, but because I couldn’t believe how many people in the comments got the answer wrong. To the best of my memory, the image read:
6 − 1 × 0 + 2 ÷ 2
One commenter thought this was a trick question, so she was trying to answer “IT” and got a solution of “e”. I still haven’t figured that out, but based on the number of incorrect responses, just evaluating the expression was enough of a challenge with no tricks involved. Now, since this is apparently a challenging question, I will go ahead and tell you the answer is 7. Not 1, not 5, not 3.5, not −1, but 7. Positive 7.
What people forget is order of operations, and this is only part of what bothers me. So, this got me thinking, “What should high school graduates be expected to do?” In my mind they should be able to evaluate simple expressions, solve simple equations for a single variable, deal with fractions – you know, basic math. I do not expect the majority of people to remember how to do trigonometry, solve systems of equations, or understand calculus, but is it too much to expect somebody to be able to solve for 𝒙? Is it too much to evaluate the above expression?
Initially this is what bothered me. If I were to be generous, maybe one person out of five got the correct answer. But what troubled me more is that the commenters didn’t seem bothered by getting the wrong answer. It didn’t appear they read through the previous comments and saw other answers that conflicted. They didn’t seem to notice the comment from the math teacher explaining exactly how to evaluate the expression. They just put their (wrong) answers and went about their lives. Some were even quite sure their incorrect answers were not.
But there was one other comment that really made me realize there are people who think in a way that makes no sense to me; one person answered it in two different ways. This person said if you do it this way, you’ll get this answer, but if you do it that way, you’ll get that answer, as though there were two ways to look at the same problem.
This is math, people! There are not two acceptable ways to evaluate the expression!
Since shortly after starting algebra, I’ve been of the mind that the biggest key to understanding basic algebra is a fundamental understanding of the equals sign, and demonstrations such as this make me wonder how many people don’t actually understand rudimentary mathematics and its language.