7.3.c – Summary: Solving Word Problems Containing Decimals

Key Concepts

  • Finding the Total Value for Coins of the Same Type
    • For coins of the same type, the total value can be found as follows: [latex]\begin{array}{c}\text{number}\cdot \text{value}=\text{total value}\hfill \end{array}[/latex]where number is the number of coins, value is the value of each coin, and total value is the total value of all the coins.
  • Solve a Coin Word Problem
    1. Read the problem. Make sure you understand all the words and ideas, and create a table to organize the information.
    2. Identify what you are looking for.
    3. Name what you are looking for. Choose a variable to represent that quantity.
      • Use variable expressions to represent the number of each type of coin, and write them in the table.
      • Multiply the number times the value to get the total value of each type of coin.
    4. Translate into an equation. Write the equation by adding the total values of all the types of coins.
    5. Solve the equation using good algebra techniques.
    6. Check the answer in the problem and make sure it makes sense.
    7. Answer the question with a complete sentence.
  • You may find it helpful to put all the numbers into a table to make sure they check.
    Type [latex]\text{Number}[/latex] [latex]\text{Value (\$)}[/latex] [latex]\text{Total Value (\$)}[/latex]
    Quarter  3  .25  .75
    Nickel  2  .05  .1