At one point when I was a sixth grade English teacher, I used to buy large bags of plastic coins at the dollar store. The things were meant to be party favors, I think; they wouldn’t have served as poker chips, because they tended to split along the perimeter and fall apart. There was no precious metal involved.

I kept the coins in a drawer, and when I felt like it, I handed them out to individuals. “Whoa!” I would say to someone, “That is epic homework. Useless plastic coin for you!” and give the kid a glittering piece of flimsy plastic. Or in a poetry discussion, a kid would say something incredibly thoughtful, and I would silently go to my desk, get a coin, and hand it to him (I taught only boys, in a private school). All the other kids would go, “Oooooh,” and the child would smugly put the coin in the pencil case in his binder.

I wanted to recognize those times when someone did something unusually great. Like when a kid brought me a gnawed piece of looseleaf in a baggie as evidence that the dog had, in fact, eaten his homework. “Useless plastic coin!” everyone shouted, and I obliged.

Every once in a while, too, when a discussion was incredibly good, I would say, “Useless plastic coins for everyone!” and hand them out with abandon. I didn’t do it too often, because it would mean I had to go back to the dollar store.

I gave the kids lots of opportunities to earn those coins. For instance, every day I wrote the date on the white board, and after the first week or so, I started deliberately making a mistake in the date. The first person who found the mistake got a UPC (useless plastic coin).

I started out the year with easy mistakes, like the wrong day of the week or a misspelled word. By the end of the year, the mistakes were very, very difficult to find. For instance, I would write the date in a simple transposition cipher (A=M, B=N, etc.) but make a mistake in one letter. Or I would write the date upside down but with one number right side up, or everything completely backwards except that I would write the wrong day of the month, day of the week, or year. I would leave out a comma, or write the date on an undulating line except for three letters that were absolutely on a straight line.

This made the beginning of class a little chaotic and distracting (I only ever did it for the first five minutes of class, and said, “too late!” if anyone tried to guess after that), but that was all right because it allowed me to hand out papers, check completed homework, confer with individual kids, or let those one or two kids who were always late sneak in without being noticed.

The date taught them the rudiments of cryptography, and to be aware of the calendar. It also gave me five minutes in which to glance at their homework.

I really, really didn’t want to collect and grade homework, so I walked around with my class folder and checked off that it was done, then stamped it rapidly with one of my stamps and an ink pad. There was a different stamp every day. I had a drawerful of those stamps, too. That way, when a kid furtively did his homework in class and tried to tell me I hadn’t collected it, I could say, “It isn’t stamped,” and show him the big circle in my class folder next to his name, and he would skulk back to his seat.

Then I had to fill out a homework notice. I hated those.

I didn’t really believe in homework, and I didn’t want to collect it. A massive meta-analysis in the Review of Educational Research found no benefit to homework in elementary school, and very little in middle school aside from good habits. But I was supposed to assign homework, so I did. I didn’t want to send homework notices home to the parents; they were annoying for everyone. I just wanted the boys to know I was going to check it.

I did check homework, though. There was really only one good reason for having homework, and that was to catch up with kids who were faking understanding. Kids would go to great lengths to conceal that they didn’t know what was going on. I could tell at a glance if a kid understood, and I would make a quick note next to that kid’s name if he didn’t. Then I would say, “Come to me tomorrow during homeroom. Five minutes. That’s all.”

Then, the next day during homeroom, for five minutes, I would have him sit down and do a couple of problems. I kept to the five minutes promise, too. I set a timer. Then I gave him a useless plastic coin for showing up, and sent him on his way. It was remarkable how five minutes of one-to-one work could help a kid understand almost anything.

You better believe I hunted those kids down if they didn’t come to me. I was remorseless. My students found out very early that it was very easy to do what they were supposed to do, and really hard to avoid doing it.

The boys were careful about their coins. They didn’t lose them, or let other people steal them. Occasionally of course, someone would drop one in the hall, and a kid would bring it to me doubtfully and say, “I found someone’s useless plastic coin,” and I would say, “Thank you for letting me know,” and let him keep it.

Sixth graders can lose anything, so their carefulness with those coins was extraordinary.

How good were they at losing things? At one point, I ordered custom-printed pencils that read, “Dr. Turner has my shoe,” because if they came to class without a pencil I would give them one of those pencils, and demand a shoe in return. Those pencils still disappeared. And somehow the shoes did, too.

When a boy collected ten coins, he could redeem them for a dress-down day. That was a big deal because those kids had to wear button-down shirts, a blazer, proper trousers, leather shoes and a tie, so the opportunity to appear in school in an immense football jersey and basketball sneakers was exhilarating. “I have ten useless plastic coins,” a boy would say, appearing at my desk and spilling out the coins. He would count them out and I would gravely fill out the form for him. And if he said in dismay, “I had ten!” after he had counted them out, I would say, “Yeah, someone turned in one of yours. You dropped it in the hall.”

The coin economy was a reward system, and teachers usually use those systems for behavior management. I didn’t have behavior problems for the most part, so used the coins for two reasons: to encourage initiative and independent thinking on their part, and to avoid too much record-keeping on my part. And also to make eleven-year-old kids say “useless plastic coin” over and over again, because I have a puerile sense of humor.

My last year of teaching, I was just too tired to do the date any more, or the coins, and that tiredness was one of the main reasons I retired from that job.