Put your mathematical thinking cap on--because even though these puzzles are toughies, they take insight and brainwork to solve, not a knowledge of calculus or linear algebra or any other kind of advanced math. Consider for a moment: * How can you divide a regular pentagon into five identical pentagonal shapes? * What is the only decade in American history to contain four prime-numbered years? * What three right triangles with integer sides have areas numerically equal to twice their perimeters? Don't worry if the answers don't spring to mind immediately; you'll have plenty of company. Compute without calculators; study the "survival of the splittest" by arithmetically analyzing a little amoeba reproduction; and investigate whether or not a rich man's children are getting a "square deal" with their inheritance. Just don't give up, because you'll have a lot of satisfaction when you figure them out.