How I Use It
This game asks students to problem-solve and add and take away blocks to help capture the blobs. The students enjoyed the game but it didn't seem to help them with the math concepts of adding and subtracting. As the levels increased, they needed to pay more attention to the needed blocks but for most it was about solving a problem, and they didn't seem to build their number sense or algebraic thinking . I suppose if they played it enough, it might help with their ability to "see" how many blocks are needed (and so would be able to pick the correct tool and the number more quickly), which could lead to better estimation skills. I would use this game as fun way for students to work on problem-solving and critical thinking skills--as an extention or a "when finished" game.
If my objective is to teach addition and subtraction (and multiplication and division), I would not use this game. My ratings above were based on this as a problem-solving game. As the students (and I) played it, they had to think about their strategy for solving the problem (i.e. getting the blobs into the machine without the blobs escaping). Since there was a time contraint, students had to strategize about which steps they needed to take in which order. Students enjoyed the game and kept clicking on "next." The "excellent" job was a bit repetative and annoying since the students received it after each level.