Piyo Math

This is a completely free app named "Piyo Math." This app is a game that uses given numbers and four arithmetic operations to create an equation equal to a target value. There are levels 1 through 12, each with a different difficulty level. In total, there are more than 8,000 problems available, so you can enjoy it for a long time. This app is recommended for those who are interested in mathematics as well as for those who want to train their brains.