History of Mathematics

It was interesting to find out that the earl humans used clay to count, i didn't know that. Also I am surprised on how much work it took for cultures to calculate and the many steps they took to do one simple division problem. I really like the part where the roman numerals were explain and the abacus because i didn't know how to read them or use them. If none of these civilizations thought of ways to complete this whole math and trading thing, we would be really far back in what we know... Also, I was very interested the whole 7 minutes :). I guess i learned some new things today in math!