Community wiki answer so the question can be marked as answered: As Abstraction pointed out in a comment, there is no such strategy (except in. Color 21 at Cool Math Games: Practice addition skills in this endless stacking game. Stack the different color 21 orbs on top of each other until they add up to. cool math game 21 on Scratch by xe16genesee. cool math game by xe16genesee. scripts. sprites. See inside. Oh no! We're having. This game requires a huge amount of concentration and memorization as you run or skate through the 3 dimensional courses. What interesting theorem can I present to an audience of CS students in 10 minutes? Nim Games — Lesson Plan. In a game players take it in turns to say up to 3 numbers starting at 1 and working their way up and who every say's 21 is eliminated. I see, but is there a strategy which would reduce your chance of losing over just online casino with free bonus random numbers in your interval? Solve as many problems as you can before time runs out to get a high score. See if you can find a winning strategy including when it is better to go first or second.