The Mexican Seven-Layer Dip that we usually put in an 8×8 glass dish and cover with foil needed to go in a plastic container with different proportions. That’s because I needed a container with a plastic lid so that I could put other food in our very full refrigerator on top of it. (Putting heavy things on top of foil tends to end in disastrous results.)
How was I going to be sure that my plastic container would be big enough?
This was a job for…MATH!
I had to find out if the volume of the plastic container was equal to or slightly greater than that of the 8×8 glass dish.
Why volume?
Because it’s the amount of space something takes up in a container. I had to be sure there was enough space for my dip so that I wouldn’t have to omit any vital ingredients like black olives or cheese. (I can’t live without those.)
Finding volume of a rectangular prism is a pretty easy task to do. It’s just length x width x height. No amount of advanced calculus is required. (Whew!)
Now I could have figured out the volumes of the two containers by myself, but I decided to be a good mom and let my teenage math whiz do it. (It’s a learning experience, after all.)
I told her what I needed to know and gave her the containers, a ruler, a piece of scratch paper, and a pen. Here’s what she figured out:
The glass dish was 8″ x 8″ x 2″. So it had a volume of 128 cubic inches.
The plastic container was 11 1/2″ x 7 1/2″ x 2 1/2″. It’s volume was 215.625 cubic inches. (We converted 1/2 to .5 because sometimes decimals are easier to work with.)
Is 215.625 > 128?
Yes it is. So the plastic container was big enough for the Mexican Seven-Layer Dip with a little added space for extra black olives and shredded cheese. (YUM!)
So you see, finding volume has its practical applications in life beyond just math homework.
Looking for other ways to show your kids math in action? Susan Evans has some hands-on ideas for getting kids excited about math as well as other teaching tips in her audio workshop, Overcoming Math Frustration. It’s a really helpful resource. You can get to it by clicking on my paid link here: Overcoming Math Frustration. (I earn a small commission from the sale of products purchased via paid links. Please see my disclosure for details.)
Enjoy!