Bubble Calculater

Demo to a upcoming android game I have been working on. You have to solve equations by matching numbers together. The equations will become progressively harder. This game also has two separate game modes, the first is Free Play where it gives you random equations from a set difficulty. The second one is Time Attack, you have to beat an entire difficulty as fast as you can, a way to test yourself that you are learning.

Any feedback is very appreciated. The point in uploading this is to figure out whether the game is fun or not.