The simple interest formula is I = Prt (Interest = Principal * rate * time). This is one way that interest is calculated on a loan or investment.

Create a loan scenario: Tell a story about the purpose of the loan, who was involved, and explain the terms and conditions of the loan. Present your scenario to the class; make sure it includes values for three of the four variables for the simple interest formula. Do not solve the problem, but let your classmates complete the solution.