If you were a child in the 80s or 90s then you might very well have a weird affection for Math Blaster. This, along with other classic edutainment titles, took over the classroom and made it okay for kids to play games in school long before Minecraft.
JumpStart announced that Math Blaster is getting a comeback via mobile. This free to play game puts players in an online 3D world to learn about different aspects of math. Some examples of math covered include the basics of addition and subtraction to long-form math.
Math Blaster might no longer be of use to you, but modern child out there might find it a useful way to figure out a tough concept or two.