In this activity, students act as food vendors selling products. It focuses on money through counting, making change, exchanging amounts, and adding/subtracting (often including borrowing). Each student has a shop with prices set for the item (differentiation options) and his/her classmates come through to buy items. Students then exchange money and write down the transaction on their "balance record" sheet.
This reaches every aspect of the Common Core Standard 2.MD.C.8. All materials are included in the product, including an instruction sheet. This activity is designed for groups of four, and would be a great addition to a math center.