Using Decimals in Money Applications
Using Decimals in Money Applications
We often apply decimals in real life, and most of the applications involving money. The Strategy for Applications we used in Mathematics 102 gives us a plan to follow to help find the answer. Take a moment to review that strategy now.
Tip: Strategy for Applications
- Identify what you are asked to find.
- Write a phrase that gives the information to find it.
- Translate the phrase to an expression.
- Simplify the expression.
- Answer the question with a complete sentence.
Example
Paul received \(\text{\$50}\) for his birthday. He spent \(\text{\$31.64}\) 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. | \(\$50\text{ less }\$31.64\) |
| 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 \(\text{\$3.529}.\) How much does Jessie owe for the gas? (Round the answer to the nearest cent.)
Solution
| What are you asked to find? | How much did Jessie owe for all the gas? |
| Write a phrase. | 8 times the cost of one gallon of gas |
| Translate. | \(8\left(\$3.529\right)\) |
| Simplify. | $28.232 |
| Round to the nearest cent. | $28.23 |
| Write a sentence. | Jessie owes $28.23 for her gas purchase. |
Example
Four friends went out for dinner. They shared a large pizza and a pitcher of soda. The total cost of their dinner was \(\text{\$31.76}.\) If they divide the cost equally, how much should each friend pay?
Solution
| What are you asked to find? | How much should each friend pay? |
| Write a phrase. | $31.76 divided equally among the four friends. |
| Translate to an expression. | \(\$31.76÷4\) |
| Simplify. | $7.94 |
| Write a sentence. | Each friend should pay $7.94 for his share of the dinner. |
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 \(\text{\$0.22}\) each and \(4\) oranges that cost \(\text{\$0.49}\) each. How much is the total cost of the fruit?
Solution
| What are you asked to find? | How much is the total cost of the fruit? |
| Write a phrase. | 6 times the cost of each banana plus 4 times the cost of each orange |
| Translate to an expression. | \(6\left(\$0.22\right)+4\left(\$0.49\right)\) |
| Simplify. | \(\$1.32+\$1.96\) |
| Add. | $3.28 |
| Write a sentence. | Marla's total cost for the fruit is $3.28. |
This lesson is part of:
Introducing Decimals