Geometry:

3.14159265358979323846264338327950288 . . . etc.

 

Today's Snack: Pi is an endless number. Make yourself an endless supply of popcorn in a tall bowl. You'll keep reaching and reaching, and it never seems to . . . uh oh, a bowl of tasty popcorn might come to an end after all! Enjoy ice water with a twist of lemon in it along with your popcorn treat.

 

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Supplies:

Flexible measuring tape, such as seamstresses use

Scratch paper and pencil | several circular items

 

 

"Pi" (pronounced like apple "pie") is a Greek alphabet letter. In symbol form, it looks like this:

 

π

           

You remember that the circumference of a circle is the distance around the circle, and the diameter is the distance across the center of a circle.

 

What do those have to do with pi? Plenty.

 

The ancient Greeks figured out that if you divide the circumference of any circular object by its diameter, it'll always turn out to be a number around 3.1416.

 

The numbers after the decimal point actually go on into infinity, with no particular pattern repeat, so it's a fascinating situation. Knowing about pi is really important for understanding the relationships between objects in everything from manufacturing design to space exploration.

 

For example, did you know that the Earth's circumference is about 24,902 miles, and its diameter is about 7,927 miles? If you round the diameter up to 8,000 miles, you can see that the circumference is a little bit more than three times as long as the diameter. Use a calculator, and you'll see just how close it comes to pi - it's "off" by a couple of thousandths only because we haven't given you the exact mileage, to the decimal points. But you can see the relationship.

 

Want to see for yourself? OK, take a flexible measuring tape, a piece of scratch paper and a pencil, and let's make a chart. We've suggested some circular objects to get you started, but bet you can think of many more to measure. Note that many measuring tapes show inches as well as millimeters and centimeters, so take your pick. Just be sure to use the same unit of measurement (inches, feet, millimeters or centimeters) for both measurements - the object's circumference as well as its diameter:

 

Round Object                Circumference        Diameter             Circumference

                                                                                                                Diameter

 

Quarter

 

 

Jar lid

 

 

Pop can

 

 

Dinner plate

 

 

Wastebasket

 

 

Basketball

 

 

Car tire

 

 

More ideas: