Using Decimals in Money Applications

Learning Outcomes

• Translate expressions from a given scenario
• Answer a question by using operations on decimals

We often apply decimals in real life, and most of the applications involving money. The Strategy for Applications we used in The Language of Algebra gives us a plan to follow to help find the answer. Take a moment to review that strategy now.

Strategy for Applications

1. Identify what you are asked to find.
2. Write a phrase that gives the information to find it.
3. Translate the phrase to an expression.
4. Simplify the expression.
5. Answer the question with a complete sentence.

example

Paul received $50$ for his birthday. He spent $31.64$ on a video game. How much of Paul’s birthday money was left?

Solution

 What are you asked to find? How much did Paul have left? Write a phrase. $50$ less $31.64$ Translate. $50 - 31.64$ Simplify. $18.36$ Write a sentence. Paul has $18.36$ left.

example

Jessie put $8$ gallons of gas in her car. One gallon of gas costs $3.529$. How much does Jessie owe for the gas? (Round the answer to the nearest cent.)

example

Four friends went out for dinner. They shared a large pizza and a pitcher of soda. The total cost of their dinner was $31.76$. If they divide the cost equally, how much should each friend pay?

try it

Be careful to follow the order of operations in the next example. Remember to multiply before you add.

example

Marla buys $6$ bananas that cost $0.22$ each and $4$ oranges that cost $0.49$ each. How much is the total cost of the fruit?