Happy Pi Day, everyone!
Held every year on March 14 (3/14), in honor of the number pi (3.14), National Pi Day honors mathematics, and,of course, all sorts of delicious pies! Most people know that pie is a dish with a crust and a filling that can be sweet or savory. (Many consider pizza to be a kind of pie!) But what is the other “pi”? Why is it important? And, besides sounding alike, does “pi” have anything to do with “pie”? The answers center on one simple shape: the circle!
Pi represents the relationship of a circle’s circumference to its diameter. You can refer to this ratio as ‘pi’ or the Greek letter π.
Pi is a number: 3.14 to be exact. Well, 3.1415926535897932384626433832795028841971693993751058209749
470938446095505822317253594081284811174502841027019385 to be MORE exact. We could try to be even MORE precise, but…pi literally goes on forever! It’s an irrational number which means that it can’t be expressed as a simple fraction (one number divided by another). (22/7 comes close to pi, but it’s not completely accurate.)
Even though people have studied it for hundreds of years, no one has been able to determine if there’s a pattern to pi’s digits. Most mathematicians believe the sequence is random and, if that is the case, the digits of pi contain every pattern in existence and will never repeat. There’s something beautiful in the idea that circles are perfectly round and enclosed, but that the number that’s needed to define them (pi) is infinite and totally random.
Pi Day is an awesome opportunity to get your kids excited about geometry and math! Here are a few of our favorite Pi Day activities!
Make (or buy) a pie!
What is your favorite pie? At KiwiCo, some of our favorite recipes include coconut cream pie , apple pie, lemon pie, peacan pie , three-ingredient mud pie and no-bake peanut butter pie. If you don’t have time to make a pie, consider buying one from a local bakery or grocery store.
Study Pie Geometry
Serve up some pie along with a delicious geometry lesson!
- Circumference: Gently trace the edge of the pie with a knife to separate it from the pan for serving.The distance that you just traced, around the edge of the circle is called its “circumference.”
- Diameter: Cut your pie in half through the middle! The line you just cut through the center of the pie is the circle’s diameter. The diameter is the distance from one side of the circle to the other at the widest point. it.
- Radius: Now cut the pie in half in the other direction. This will cut the diameter of the pie in half. This measurement—half of the diameter—is the radius of the circle. When you cut a pie into equal-sized slices, each straight edge is a radius! The distance from the center of a circle to its outside edge—the radius—is always the same. (That’s what makes a circle perfectly round!)
Use pi to determine the geometry of your pie!
Before you eat your pie, let’s do some math!
To determine the circumference of your pie, multiply the pie’s diameter by pi. Mathematicians abbreviate this into the equation: C=dπ (ie. If the diameter of your pie is 10 inches, that will be 3.14 X 10 which equals 31.4 inches.)
To determine the surface area of the top of your pie, multiply π by the radius squared. Mathematicians abbreviate this into the equation: a=πr2 (A pie with a 10 inch diameter has a radius of 5 inches so 3.14 x (5 squared) equals 78.5 square inches of delicious topping!
Now that you know about pi, bring geometry into the kitchen whenever you bake. Are you looking for more ways to introduce your little ones to science? Check out our hands-on STEM kits for kids! They’re delivered monthly, and they bring the perfect mix of joy and learning!