traveling for work - extra week - where too with kids?

Hello docbdj. I think eight days is not too many days in Denmark. I think children at ages 8 and 10 would like being at any foreign country. I recommend being at Copenhagen, three whole days, and go on day trips to other parts of Denmark, and perhaps two nights at a town at Jutland. I think the travel guide book RICK STEVES' SCANDINAVIA has information about plenty of good places in Denmark. People in Denmark talk in the English language, and many of them are friendly to foreigners, and some Danish people are delightful. Try to see Rick Steves' video travelogue on Denmark. I think you can see it from the internet, by clicking on a place at this website.

While you're in Copenhagen don't miss taking your kids to the Tivoli Gardens, it's a wonderful amusement park for both adults and kids.
I'm very biased towards Paris. I love it there and my son has loved it since his first trip there when he was 11. It's a great city for kids. And there are day trips from Paris my son loved... the castle of Vaux-le-Vicomte (where the movie "Man in the Iron Mask" w/Leonardo diCaprio was filmed) for instance.

In Denmark but outside Copenhagen, I think these sites are both kid- and adult-friendly:
* Roskilde town for the Viking Ship museum and for the Cathedral with royal tombs
* Frederiksborg Castle - "the Danish Versailles"
* An open-air folk museum, such as Den Gamle By in Arhus
* Legoland
* Aero island for very charming village architecture and beach opportunities.
All the above are reachable by train, plus bus from Jelling to Legoland and ferry from Svendborg to Aeroskobing, but driving is also not difficult and distances are pretty short.

If the kids like natural scenery at all, consider the island of Bornholm.