I typed "10,000" and was told that I was right because I had a typo. There's a pretty big different between "100000" and "10,000", but OK.
This is a common area of confusion.
万 = 10,000
千 = 1,000
There is no equivalent of million in Chinese. A million is written as 百万, ie. a 100 of 10,000.
Yeah, this is simply because Duolingo allows single-character mistakes in English. It's not always ideal. But at least you get an indication that you've made a mistake.
Seems like an awkward phrase in English. Maybe "We hold a hundred thousand yuan in capital?"
Also "We have 100 thousand in capital."
Would better if it is "We hold/have a capital of one hundred thousand yuan."
And without the "one"?