When I first started utilizing math games (as part of the Investigations Math Curriculum), I was rather skeptical about their efficacy. For one, it was hard to tell if my kiddos were really doing any math while they were playing with dice and cards. Secondly, even if they were doing math, they weren't producing any "evidence" that could be checked or graded so I couldn't know if they were correct.
As I learned more about how to instruct students to communicate while playing math games, I became more confident that my kiddos were actually doing math. I also found ways to have them record their responses, like keeping score in other games, so I could confirm that they had done the math correctly. In addition, I became more adept in matching students to partners who could provide appropriate challenge and support while playing together.
Nevertheless, I wasn't really convinced that all math classes should include math games until I switched to a school that did not use games at all. I was initially looking forward to trying a direct-instruction approach to teaching math. I expected that my students would be better able to comprehend difficult concepts like "counting on" when they were explicitly taught. I also thought that management during a direct-instruction lesson would be easier.
Here's what I realized... math is challenging no matter how it is taught and, just like other skills, like reading or riding a bike, kiddos need to have lots practice doing math to really get it. After I taught a direct-instruction lesson, I noticed that my kiddos would solve a few problems and then get bored and tired. Management became more difficult when they felt overwhelmed by a packet of worksheets.
Despite the direct instruction approach my new school was using, I started introducing a few math games to my first graders. I realized that there were many other benefits to math games that I'd previously taken for granted. Specifically, math games are fun! Teaching a lesson on how to "count on" was only one part of having students understand and be able to use this strategy. Playing math games, like "Roll and Record" with a number cube and a dot cube, gave my kiddos sufficient practice thinking of a number and counting up the dots in a fun way. Unlike simply completing more worksheets, math games also provided just enough variation to keep kiddos actively thinking about the new strategy they were using.
I'm now back at my previous school, teaching a new grade, and learning new math games. Recently, two of my kiddos came over in the middle of a debate about a math game I'd just taught them -- a decimal version of the card game War. One kiddo said that his card (0.81) had won and the other disagreed (he had 0.9). As I listened to each of them explain his side, I heard them using the math language I'd taught them: hundredths, tenths, decimal, and equivalent. Before I even had a chance to weigh in, the kiddo who had insisted he'd won said, "Oh yeah! You're right: 0.9 is greater! Okay, let's keep going!" and off they went to keep playing! I feel confident that conversations like this, where kids are teaching each other and having new realizations, would not have surfaced had they been working independently to solve the same problem on a worksheet.