"umur" means "age". So this can also be translated as "my age [is] 10 years [old]". This course is still young and translations will be added in the future.
A lot of these phrases require the "most correct" way of saying it, which makes placement hard unfortunately for those of us who have studied the language as a second or third language elsewhere. Whilst my English-speaking brain translates this as "my age is ten years old" the most correct format is "I am 10 years old" even though it 'technically' is presuming context.
Literally, I think yes. It sounds a bit weird though, as no one would actually phrase it that way in English, so that's probably why it was marked wrong, and they only have that 1 translation in as correct.