This app has three modes.
In Lesson mode, you answer ten questions by choosing the answer that matches the formula from two options.
When you achieve a certain score in a lesson, the Challenge mode for that lesson is unlocked, and you can move on to the next lesson.
In Challenge mode, you can choose the time limit from 10, 30, or 60 seconds
and compete to see how many questions you can get right.
As you progress through the lessons, you will also unlock the Test of Skills mode.
In Test of Skills mode, you will not only be able to choose from two-option calculations, but you will also be able to measure your calculation ability by your score, with questions that require you to find the error in the formula or solve the calculation and enter the answer.
There are three levels of Test of Skills: Bronze, Silver, and Gold.
You can clear the Test of Skills mode by achieving a certain score in each level.