Here’s a simple number game to play on a rainy day, or while sheltering in place. You and I take turns crossing out numbers from the list {1, 2, 3, …, 9}. The winner is the last person to cross out a ...

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A prime number is a whole number greater than one that has exactly two factors. Those two factors are one and the number itself. This definition is found across many school curriculums. Examples ...