Well I wouldn’t accept “I dunno” as an answer any more. “you are old enough now that it’s time for you to know because if you don’t people will take advantage of you”.
Every time they say ‘I dunno’ demand a single page report on the answer complete with at least 2 sources. No TV/Phone/Whatever until it is done. They’ll stop uttering that real quick. The key is co-participation though. Telling them something is important is meaningless when compared to showing them it is important by sitting down and helping them figureidout.