May is National Inventors Month, when we celebrate all the cool things that make our lives better: the refrigerator, your light-up sneakers, or that one cool Lego piece that everyone fights over. Sometimes inventors try to solve a problem but do the project wrong — and end up solving a different problem instead! The microwave, potato chips, and our favorite, the warm-center chocolate cake were all accidents — and they’re all worth celebrating!

*Wee ones:* The microwave oven was invented when a scientist’s new tool melted a candy bar. If you microwave a candy bar, a stick of butter, and an egg, how many foods do you microwave?

*Little kids:* Warm-center chocolate cake — which gushes yummy chocolate sauce when you slice into it — was born when a famous chef undercooked a cake. If he cooked it for 7 minutes instead of 9, by how many minutes did he fall short? *Bonus:* If he also cooked it at 300 degrees F instead of 100 degrees hotter, what temperature was he supposed to have set?

*Big kids:* Fireworks were invented 2,000 years ago when a cook packed charcoal, sulfur, and saltpeter into a tube and set it on fire, which made it explode. If you mix 3 tablespoons of charcoal, twice as much sulfur, and twice as much saltpeter as sulfur, how many tablespoons of stuff do you mix? (Note: This is not the real recipe, but please DO NOT try it!) *Bonus:* If each tablespoon makes 10 sparkles in the sky, how many sparkles does your mixture make?

Answers:

*Wee ones:* 3 foods.

*Little kids:* 2 minutes. *Bonus:* 400 degrees F.

*Big kids:* 21 tablespoons, since you mix 6 spoons of sulfur and 12 spoons of saltpeter. *Bonus:* 210 sparkles.