One is one … or is it?
Wait For It…The Mongols!: Crash Course World History #17
One bag of apples, one apple, one slice of apple — which of these is one unit? Explore the basic unit of math (explained by a trip to the grocery store!) and discover the many meanings of one.
Lesson by Christopher Danielson, animation by TED-Ed.
View the full lesson: http://ed.ted.com/lessons/one-is-one-or-is-it