Here’s how I divide my morning commute to Hyde Park: Fifteen minutes of Duolingo French à pied from home to the UP-Northwest stop. Ten or so pages of a novel—currently Thomas Pynchon’s Vineland—on the downtown-bound train. The last leg, aboard the 192 express bus, is reserved for Khan Academy. At 58, I’m ready to conquer fractions and decimals.

At 8, long division broke my brain. Memorizing the times tables was tough but doable, and basic division reverse engineered what I’d just learned. But when the dividends stretched to three and four digits, a chasm opened, crash-landing me at “the slow table,” the label our teacher had slapped on the benighted group at the back of the room. This was Georgia in the 1970s, where (just for context) corporal punishment was still accepted pedagogical practice.

When my family moved to progressive Minneapolis a couple years later, I was enrolled at the neighborhood “open” school. There was no discernible curriculum—circle time could be a couple chapters from Judy Blume or, if the teacher had been to the movies the night before, a blow-by-blow retelling of The Deer Hunter—and students were free to pursue what interested them. My curiosity about numbers ended with Reggie Jackson’s batting stats, so I became an expert in dodging math. In high school the algebra and geometry teachers, unprepared for the remedial challenge I presented, just waved me through with C’s, focusing their energy on the math team kids.

Not surprisingly, my math SAT score could barely roast a chicken. For years I claimed (and half believed) that my essay had dazzled some UChicago admissions officer, but the College’s then–81 percent acceptance rate was likely the more decisive factor. There was just one problem: Before I could take physics, as the Core still required, I would need a year of Essential Mathematics.

In the fall of 1985, this class (aka “Math for Rocks,” the implication being that we “slow table” alumni were destined to fulfill our physics requirement via geology) met in Eckhart Hall at eight-thirty in the morning. The ideal hour to teach math to 18-year-olds who couldn’t find a lowest common denominator if they cheated off a Fields medalist. I failed and got to repeat the class as a second-year, albeit at a more humane 11:30 a.m. I passed, thanks only to math and physics major friends, brothers-in-arms who also supported me through Physics for Poets—take that, Rocks for Jocks—refusing to leave my hobbled brain behind.

For the next two decades, I could ignore math, provided no one asked me to divide a tapas bill 12 ways. Then kids arrived. I helped with homework through fourth grade, then my wife, also an English major, took over. By the time her limits were being tested in junior high, both our daughter and son had great teachers who could light the path forward.

They also had Khan Academy. The free online platform, outgrowth of the math tutorials that hedge fund analyst Sal Khan created for his young cousins, was an incredible adjunct to in-class learning and a godsend for parents like me.

Several times during the kids’ years in elementary school, I gave Khan a whirl myself, thinking it might bridge the gaps in my math education. But each time, it was clear there weren’t just gaps; the entire foundation was missing. Staring into the abyss, I would scurry back to my novels and political biographies.

Last year, however, as our son and daughter cruised through algebra II/trig and differential calculus, respectively, I swallowed my fear (and pride), opened the Khan app on my phone, and clicked into second-grade math. (I was confident, at least, in my knowledge of the basic shapes and single-digit problems covered in the pre-K through first-grade modules.) From that point on I’ve watched every video, taken every quiz, and passed every unit test. I’ve gone deep on place value, number patterns, and reasoning. Khan teaches the why behind the standard algorithms, which always felt arbitrary; as a result, division, decimals, and fractions now make a lot more sense to me.

“I don’t mean to brag,” I texted my daughter shortly after she started college last fall (as a math major), “but I’m CRUSHING equivalent fractions.” “Yay for learning,” she replied, adding thoughtfully, “this is not sarcastic.”

I’m now three-fourths of the way through fifth grade. My goal is to reach calculus by the time my daughter finishes college. It’s ambitious. I can do more complex problems in my head, but I’m also making the same sloppy mistakes the kids did at this level. My excuse: I’m trying to solve 5268.39 x .074 while hurtling down Lake Shore Drive at 60 miles an hour. Because I’ve ditched the slow table for an express bus.

Are you smarter than a fifth grader?

How about a 58-year-old English major who has taken arms against a sea of troubles—decimals, equivalent fractions, and the like? Grab your pencils. It’s math time. Answers at the bottom of the page. 

1. It’s the Sunday night before finals. On Friday you have three exams and a 15-page paper due. Monday through Thursday, you plan to spend four hours a day studying for each exam and five hours a day on the paper. But your a cappella group, the Harper-si-Chords, has two-hour practices on Tuesday and Thursday. Which equation represents the time you have to work?
      A. 4 x 3 x 4 + 5 − 2
      B. 4 (3 x 4) + 5 − 2 x 2
      C. 4 (3 x 4 + 5) − (2 x 2)
      D. 4 (3 x 4 + 5 − 2) x 2
2. 18.9 ÷ 7 =
3. 6,420 ÷ 102 =
4. 5/4 x 6 =
5. You’re at your 35th College reunion with your partner and three kids. At 20, you could put away four slices of Giordano’s—half a pizza—and still be up for some three-on-three at Henry Crown. So you order two stuffed pies: one pepperoni, one sausage and mushroom (your old go-to, shrimp and black olive, is no longer on the menu). You also get a tavern-style thin crust with 24 slices. At 58, you can eat only half your former total. Your partner and oldest kid eat half a slice of deep dish each. Everyone makes two-thirds of the thin crust disappear. How many slices of pizza will you be carrying around for the rest of the day?

Answers: (1) C; (2) 2.7; (3) 64.2; (4) 7 1/2; (5) 21