I've been to two of these previously, one in Trømso and one in Trondheim. In both places I had roles in the children's day, giving math shows and organizing . After the prize award ceremony and lectures and party in Oslo, the winner goes to another city in Norway the next day where there is a math learning event for school children (usually somewhere around 8th grade), more lectures, and another party.

Mind you the Abel prize winners are usually quite old, I think only one has been younger than 70. They are usually quite tired after day 2.

The party in Trømso is one my top memories in Norway. Trømso is far north in the arctic circle. We were a small group of about 25 for dinner and drinks. The mayor of Trømso, in all of his mayoral bling, wrote and sang a song for the Abel prize winner. In Norwegian tradition, there were many speeches and funny stories during dinner, and because the winner was not Norwegian it was all in English, which I appreciated at the time.

Here's a link to the cool thing we built a couple of years ago in Trondheim: http://www.matematikksenteret.no/content/2212/Abelprisen-og-et-digert-tetraeder