Pebbles wanted to buy a scarf but they were out so he bought a hat instead. 

Scarcity forces trade offs: What we want is not unlimited and so we might have to make a trade, where we get one thing in place for another.

Pebbles then wanted ice cream and his friend, Tux offered to pay for him if he picked Tux up.

Incentives Matter: Rewards or punishments that motivate peoples behavior in predictable ways.

Pebbles and Tux decided that the benefit of getting ice cream and spending time together was greater than the cost of it.

Cost vs. Benefits: People make choices based on the expected cost and benefits of something. They can choose a good thing if the benefits are greater or a bad thing if the costs are greater.

Because they spent the money on ice cream they didn't have enough to buy something to drink afterwards. 

Future Consequences Count: Decisions made today will have an intended or unintended consequence not only today but in the future too.

The next day, Pebbles decided he needs shoes. But he is going to buy them instead of trying to make them himself.

Trade Makes People Better Off: Focus on what we do well and trade with others, we end up with more and better choices than trying to do it ourselves. 

Pebbles went to the farmers market and saw that the Apples were $8.20 a bag but last week they were $10.25 a bag. He realized he had a deal due to a drop in pricing.

Markets Coordinate Trade: Free markets do better than anyone at coordinating exchanges between sellers and buyers.

After the farmers market, Pebbles went to get pizza and after eating 2 slices, he decided to eat one more instead of the whole Pizza.

Thinking at the Margin: We think in terms of a little more or a little less instead of changing something by a lot.