We converted our classroom into a flat world with only 3 continents, because that is what the main belief was in the time of Columbus. Then we had items to trade: woolen and metal items from Europe and silk, ceramics and spices from Asia.

We tried going over the Urals and the Caucasus Mountains but that was too risky and deadly. So we tried sailing around Cape Horn and the sea was too dangerous.

So Columbus, with his idea that the world was round, went to the kings of Portugal and England asking for ships. They thought he was crazy so he went to Queen Isabella of Spain who gave him three ships.