This game was added to the Sandpit for the following reason: Incomplete
The game appears to be unfinished, or is a demo of a longer work which has not yet been completed. Once the game has been completely written, it may be re-categorised.
5 + 5 = 10 is an equation (which may or may not be true, depending on what you clicked).
5 - 4 = 9 is also an equation (which may or may not be true, depending on what you clicked).
TIPS: Try to use quest gamebook/text adventure. It helps more often with these types of simulators.. Please don't make it like one of my boring math classes. Make it funny, cool, and not boring.