Arithmetic Master

The gameplay includes compiling a series of correct arithmetic identities of various levels of complexity. The initial difficulty level involves filling in one missing digit from 1 to 9. For example: 1 + n = 5. The highest difficulty level suggests filling all components of a mathematical expression, including two operands and digits in the 1-99 range. For example: a + b * c = d.
For each successful round, the player receives experience points. The number of points received is affected by the time of the round, the number of extra moves and the coefficient of complexity of mathematical expressions. The user's game level increases in base the required number of points collecting and the difficulty gradually increases too. Also, the player has the opportunity to choose the desired level of difficulty for a relaxing or more intense process.