Math King is a free puzzle game developed by Verschueren Geert for Android devices. The game aims to test your math skills by applying mathematical operations to the given values and reaching the goal.

In Math King, you need to select a result value, the operator to apply in the formula, and then the second result value to reach the goal. Each given goal has at least one solution with a minimum of two operations to rule out single-operation wins. You have 90 seconds to solve the puzzle and become the King of Math.

One of the unique features of Math King is its undo option. When you're in the middle of building an operation, the undo option will remove the current incomplete operation. However, if you didn't start a new operation yet, it will remove the last result line if there is any.

Overall, Math King is a fun and challenging puzzle game that tests your math skills and keeps you engaged.