Big Calculator: How Texas Instruments Monopolized Math Class

These $100 calculators have been required in classrooms for more than 20 years, as students and teachers still struggle to afford them

This fall, Stephen Thompson began his first year of teaching Algebra 2 and college prep classes to 11th and 12th graders at a public high school in northwest Baltimore. On top of the typical stress of any first-year teaching experience, Thompson realized that along with other out-of-pocket classroom expenses, he would have to buy a pricey piece of classroom equipment: graphing calculators. Specifically, Texas Instruments graphing calculators.

“The students, for the most part, don’t have calculators,” he told me in October. “On a typical day, a lot of students don’t even have a pencil. It’s up to the teacher to provide that stuff. The expectation is that we will have TI-83 calculators — that’s just what the curriculum demands.”

Planned obsolescence is deeply ingrained with most tech companies. Apple introduces a new, sleeker iPhone every year, with improved features, different sizes, more power, and more pixels. But Texas Instruments graphing calculators used by high school students 10 or 20 years ago are essentially the same ones students use today. Bulky and black, with large, colorful push buttons and a low-resolution screen, TI graphing calculators resemble top-of-the-line design from the 1990s and are functionally the same as when Texas Instruments first launched the TI-84 Plus in 2004. Even the price has remained almost the same. When my mom bought my TI-83 Plus calculator for ninth-grade math class in 2006, it cost $90 at our local Staples. Today, that calculator sells for $105 at Office Depot.

I remember feeling a pang of guilt watching my working-class single mom hand over her debit card to the cashier. On the short drive home, I held the calculator in my lap, still in its blister pack. I was 14 years old, and this was the most valuable electronic device I ever owned. I was taking Algebra 2 that year — the advanced class for freshmen at my public high school — and purchasing a graphing calculator felt like an academic rite of passage. I wasn’t a math person, just a good student who’d eventually slog through Advanced Placement calculus and statistics in pursuit of some college credits.

“The expectation is that we will have TI-83 calculators — that’s just what the curriculum demands.”

Other students put games on their calculators, or decorated the lids with stickers or the colorful tinfoil from sticks of 5 Gum, or filled their calculator with hints to help them on tests, or took out the batteries in the back and used the empty space to hide drugs. (Okay, the last one was a rumor.) But I only remember using the text features to send messages to friends during class.

I grew up in a very good school district in an affluent central Pennsylvania suburb, the kind of place where a kid who lost their expensive calculator typically didn’t have to worry about asking their parents to replace it. Class anxiety seemed practically nonexistent, except for my own, which I muted as much as possible. And if I ever left my calculator at home, I could always borrow one from the school. Sometimes it would even be a model nicer than the one I had.

Texas Instruments released its first graphing calculator, the TI-81, to the public in 1990. Designed for use in pre-algebra and algebra courses, it was superseded by other Texas Instruments models with varying shades of complexity but these calculators remained virtually untouched aesthetically. Today, Texas Instruments still sells a dozen or so different calculator models intended for different kinds of students, ranging from the TI-73 and TI-73 Explorer for middle school classes to the TI-Nspire CX and TI-Nspire CX CAS ($149), an almost smartphone-like calculator with more processing power. But the most popular calculators, teachers tell me, include the TI-83 Plus ($94), launched in 1999; the TI-84 Plus ($118), launched in 2004; the very similar TI-84 Plus Silver Edition, also launched in 2004; and the TI-89 Titanium ($128).

Thompson, like many teachers, works in a district where it’s a financial impossibility to ask students and their parents to shell out $100 for a new calculator. (Graphing calculators of any brand are recommended at Thompson’s school, and they are essential for the curriculum.) So the onus falls on him and other teachers, who rely on their teacher salaries — Thompson makes $62,000 a year — to fill in the gaps. At first, Thompson bought cheaper calculators: four-function, $3 calculators. This, he quickly realized, would be insufficient. “A lot of students were angry and actually left the class and went to the classroom of the more experienced teacher next to me and asked to borrow her calculators,” he told me.

The bulky, rectangular Texas Instruments calculators act more like mini-handheld computers than basic calculators, plotting graphs and solving complex functions. Seeing expressions, formulas, and graphs on-screen is integral for students in geometry, calculus, physics, statistics, business, and finance classes. They provide students access to more advanced features, letting them do all the calculations of a scientific calculator, as well as graph equations and make function tables. Giving a child a four-function calculator —allowing for only addition, subtraction, multiplication, and division— would leave them woefully underprepared for the requirements of more advanced math and science classes.

It’s not practical or even allowable for students to turn to more modern and possibly more accessible technology — like laptops or smartphones — to fill the gaps. “iPhones do too much,” Thompson told me. “There’s an app you can get where you can just take a picture of a problem, and the app will show you the steps to solve it. For that reason, I really can’t let them use cellphones on tests. Too many students will cheat. So I need to buy graphing calculators, and they need to be nice ones.”

To understand why teachers like Thompson find themselves in this position — and why families across the country are still paying $100 or more for a piece of prohibitively expensive technology that barely seemed to have been updated in decades — one must understand Texas Instruments and its incumbency in the graphing calculator market, and how the U.S. education system has become addicted to Texas Instruments, which has a staggering, monopolistic hold over high school math.