When You Learn Something New

Setting: I was sitting in high school, Algebra II class. The teacher, who was a talented teacher of math, needed some tape - the purpose of which I do not recall. As he picked up his tape dispenser, something caught his eye...

Upon further investigation, he popped open a panel on the body of the dispenser, and made a realization. He exclaimed "some dummy filled this with sand. Of all the pranks!" And he proceeded to dump the sand into the nearest wastebasket. He popped the panel back onto the dispenser, and went to set it down. 

Then he realized...

"Oh, maybe that was what gave it some weight," he said as he gestured with the dispenser, realizing how light it was now. 

We all had a good chuckle. 

And I learned that day that sand is put inside tape dispensers to give them a little weight.