Unit 7, Lesson 8
Money and Debts
Accelerated 6
Preparation
Lesson Narrative
In this lesson, students examine how negative numbers can be used in the context of money to represent debits or debts.
First, students consider a situation where one person owes money to another and explain why it could make sense to represent this amount with a negative number. Next, they examine a statement from a checking account. They see how representing transactions with signed numbers allows us to efficiently distinguish deposits (money put into an account) from withdrawals (money taken out of an account). As students interpret signed numbers that represent account balances and transaction amounts, they are making sense of problems (MP1).
- Apply addition of signed numbers to calculate an account balance after a deposit or withdrawal, and explain (orally and using other representations) the solution method.
- Explain (orally and in writing) how signed numbers can be used to represent situations involving money, including deposits or withdrawals and assets or debts.
- Write an equation with an unknown addend to represent a situation where the amount of change is unknown.
Let's apply what we know about signed numbers to money.
Required Preparation
If the computation requirements might get in the way of understanding that money can be represented by positive and negative values, consider providing access to calculators.