Help with reading two coins
 

I'm doing some research for an illustration I'm doing, and was wondering if you guys could help me out with a detail... See, I need to feature old japanese coins, but I have absolutely no idea of how to read the kanji on them (if it even is kanji, this girl is a japanese language novice on all levels!)
So, what I'm asking is basically this: What does these coins say?



Thanks in advance! Hope to get an answer...! :3

Left one is 天保通寶, right one is upside-down, turn it the correct way it says 當百 with the bottom just a design.

No idea what it means. It probably is Japanese, not Chinese, as in Chinese it would be something like "Heaven protect transport treasure" and "act as one hundred". But then again, my Chinese isn't very good.

Later edit: 天保 seems to be the era name for Tenpo. Note sure about the "通寶" part. So I'm guessing that "當百" means 100 units of currency.

thank you!