Why I Let Students Use Calculators All The Time

“Sure! I’d  love to have you demo a lesson!” Ms. B’s eyes widened as a smile grew on her face. I was surprised and thankful that she was so open to the idea.

“Great!” I replied. “What unit are you doing right now?”

“Well, we just finished Quadratics and we’re about to start Volume and Surface Area.” Ms. B replied, pointing to the standards list on her wall.

“Okay, so how about I introduce Circumference and Area of circles?”

“That’s fine. What do you need for that?” Ms. B asked, ever eager to help.

“Do you have graph paper, calculators, rulers, that sort of thing?” I asked.

“Calculators? You let your students use calculators?” Ms. B countered, incredulous.

"You what?"
“You what?”

Yes, I do let my students use calculators.

Here’s why:

Lifelong Need

My wife doesn’t know her times tables. She’s a university professor and will regularly grade freshman Theology papers sitting on the couch. She’ll call out while I’m cooking or playing with the baby.

“What’s eight times six?”
“What’s 27 plus 18?”
“What’s 85 divided by 15?”

I'm a walking, smiling, calculator in the Vaudrey household.
Husband: a walking, smiling, calculator

When I’m not home, she has a calculator in her pocket all the time. Even if her phone is in the other room, she can Google it.

My wife doesn’t need computational skills.


…but she needs the reasoning.

She needs to know what the average means, when to find the sum of a row and give the total student points, and how to explain to her college freshmen what it means to have 6 quizzes, each worth 10% of their grade.

"But what if I miss one? Can I still get a C?"
“But what if I miss one? Can I still get a C?”

The students in Ms. B’s classroom also have calculators in their pockets. I want them to know how to use it effectively, which is a much better use of their time than memorizing their 12s tables.

Diane Kinch, former president of CMC and board member of TODOS, gave this truth bomb at a recent workshop:

Students have had 15 years to learn their times tables and they still don’t know them. At a certain point, I have to stop boring them, give them a calculator, and say “Let’s do some math”.

In my own classroom, we use TI-83+ calculators nearly every day, which I like for a few reasons:

  • TI-83s keep a record of the last 8 or 10 calculations, so if students clear accidentally, they can recall it.
  • There are tons of other buttons that do weird math stuff that we won’t use this year. This (f0r some) serves to build creativity about what’s coming next. About 2/3 of the students found the Stats Generator application and did coin-flipping trials four months before our unit on probability.
  • They could easily show their neighbor the order of steps and describe the reasoning that led them there.

Let’s work backwards


Students who focus on reasoning instead of computation are better prepared for college and career in the US.

(It’s notable that most of the grunt work for my CPA buddy’s tax clients comes from the western coast of peninsular India. Computation is a high value there.)

That’s why I use calculators in the classroom all the time; because I think that reasoning is more important than computation.

For more on that idea, watch this by Dan Pink.

~Matt “Which one is the minus sign?” Vaudrey

5 thoughts on “Why I Let Students Use Calculators All The Time”

    1. I changed the language to make it more clear. My friend–who is an accountant–deals heavily with number-crunchers in India. Not racist; just a fact.
      1. An anecdote may technically be a fact, but basing a broad generalization (students who like computation enough to make a career out of it will need to move to India) is wrong. You even went as far as to link to India’s revenue department as if the US doesn’t have the same thing. That whole statement had nothing to do with your broader point other than to belittle. Your revised statement, while better, does not strengthen your argument either.

  1. Agreed. Henri Picciotto, former math teacher at the Urban School explained it something like this, “if they haven’t learned their times tables by the time they reach me in high school, no way am I a good enough teacher to all of a sudden have that break through with them.” And Henri is one of the best teachers I’ve observed. With calculators we can do higher order thinking problems so much faster in our class time. We do teach them to graph, but graphing takes time. I can have them throw a system of inequalities on their calcs and have a great discussion about the meaning of the graph without taking the actual time to graph for every single one.

    I do sometimes have a non-graphing calc portion of an assessment, but they can still use a basic calculator.

    My biggest question now is the new SAT. Previously calcs were allowed on SAT, ACT, and AP tests. I want to see examples of what types of questions will be on the non-calc portion of the 2016 SAT. I think it’s our responsibility to prepare students adequately for success on their college entrance exams so they have college options.

  2. I don’t know. I think arithmetic is a use-it-or-lose-it skill. I nearly always let my high schoolers use calculators, because they’re used to it and it’s not a battle worth fighting. I’m more careful with my middle schoolers, though, because they’re used to doing math by hand and I don’t want them to lose that ability like the high schoolers. have It seems to be that as soon as you let kids use a calculator, they turn their computation brains off. That being said, I’m still debating with myself how much I should let my 7th graders use calculators this year.

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