## Pi for breakfast!?

So I went to breakfast this morning.  Long story short, my friend needed to know how the sizes of two mugs compared.  The thought crossed our minds to sneak a mug out to the car and run some experiments when we got home.  Then, the fact that I am a math teacher zoomed into my caffeine-filled head.  πr(squared)h.  Of course!  Coffee mugs are roughly cylindrical.  What better time to make practical use of a formula that even I could not legitimize an answer for the age-old “When am I going to use this?” question.  Prior to today, that is.  After some rough napkin calculations, we figured out that both mugs will hold about the same amount of coffee, so she could move forward with her sale!

On a side note, I had to do the measuring of the mug’s dimensions.  Why?  “Women have always been told that this (holds up hands about 3 inches apart) is 8 inches.  We’re bad at eyeballing measurements.”  Maybe this causes some sort of depth-perception problem too, and that could explain the driving stereotype.  But I digress.  I used the cylinder’s volume formula today, and I was giddy all day.

PS – for a bonus: If one milliliter of coffee is one cubic millimeter, and my napkin calculation said that the cup’s volume was 14.7 cubic inches…how many fluid ounces of coffee could the cup hold?