When Will I Ever Use This?
An Essay for Students Who Have Ever Asked This Question in Math Class
DOUGLAS COREY, BRIGHAM YOUNG UNIVERSITY
The most-asked question in math class is some variation of “When am I ever
going to use this?” In fact, I began typing this question into a search engine, and every
one of the 10 popular completions for “when am I ever going to use . . .” dealt with
school mathematics. Now, as a student, I know this question is a compelling one. Of
course, some students ask it as a challenge to the teacher, using it to mean “Prove to me
that I need this in my life.” However, some students ask it sincerely, honestly wanting to
know how it might be used in the future.
In either case, teachers most often do one of the following. One, they respond
with some trite response about how you will need it next week on the exam or next year
in another class. Not very compelling. Two, they give the quick reply that “if you don’t
know it, you will never use it” or a similar comment that, although true, is not much
more satisfying than the first. Three, which is traditionally about the best a teacher can
do in this situation, they try to give the students what they think students want. Either
the teacher tries to tie the mathematics to some field of employment (there is a popular
poster on the Internet that helps teachers with this), or they present an application of
the mathematics to some area that might be interesting to the student or will at least
justify the mathematical topic. If you have been in a class where this happens, you
know it is rarely satisfying.
This has become a paradox that I have spent time thinking about—math is
certainly useful, yet why is it so hard to explain to or show students how it can be
useful to them? In this essay I analyze this paradox, and I give my response to the
student question, “When am I ever going to use this?”
To start off with, let’s do a thought experiment. Take a moment and think about
the last time you used multiplication outside of a school environment. It might be hard,
but try to remember. If you can’t remember the last time, try to recall at least some
time recently where you used multiplication. Think . . . Think . . . Think. Do you have
situation yet? It doesn’t have to be a time that you wrote down a multiplication
problem or worked it out on paper. You could have done it in your head or on a
calculator. If you are like me, you are having a hard time remembering a specific
situation. I had a difficult time recalling a time, yet I use multiplication all the time. It
is so ingrained in my thought process, I don’t usually notice it. I bet that is true for
most of you. I am sure that you use the idea of multiplication with its closely related
mathematical cousins of finding areas, counting things in groups or arrays, scaling
things up or down, or working with proportions. It has become such a natural a part of
our thinking that we don’t consciously think, “OK, this is a multiplication problem.
How was I taught to do this in school?”
This may be the first piece of understanding this paradox. Math is useful, but
the large majority of the use is done mentally and subconsciously. When you look at a
graph, a number, a formula, a chart, an algorithm, a quantitative situation, or anything
of the sort, you draw upon myriad mathematical connections made during the many
hours spent in math classes and doing your math homework (and in other situations) to
immediately make meaning (or begin making meaning) of what you are experiencing
(seeing, reading, and so on). Rarely could you go back and figure out when you learned
the skills, even one skill, you are using in the moment of making sense of something. It
is nearly impossible to pinpoint the moments that you learned specific skills, especially
those that create the schema we use to make sense of the world. The consequence is
often a loss of credit to the teachers who helped students learn, simply because finding
the source of the knowledge becomes nearly intractable.
Let’s get back to our thought experiment. I hope by now you have a situation in
which you used multiplication. When I first conducted this experiment, I thought of two
instances. I used multiplication to calculate the area of a raspberry patch I was putting
in my backyard so I could compare the area to some information about raspberry
patches online. I also used multiplication to quickly figure out if I had picked up enough
cans of cream of mushroom soup at the grocery store; I needed 24 cans, so I organized
them in a four-by-six array.
