WORD

Arithmetic Grade Four

Lesson One hundred and seventy-nine: Word Problems

Things get more complicated if we purchase something using one unit of measure and want the price in terms of a different unit of measure. Consider this example.


      Bob pays 16 dollars for 2 gallons of gas.
      How much is he being charged per quart
      of gas?

We are given the amount paid and the total gallons, BUT the question wants the price to be changed to the cost per quart. The first thing we must remember is that there are 4 quarts in a gallon and then we do the following.


        16 dollars / 2 gallons = 8 dollars per gallon
         8 dollars per gallon / 4 quarts per gallon = 2 dollars per quart

Here's another example:


     Sue buys 2 gallons of orange juice for 16 dollars.
     How much does she pay per pint of juice?

Here we are given the amount of juice purchased in gallons and the total amount paid for the juice, BUT the question requires that we figure out the price per pint.


           16 dollars / 2 gallons = 8 dollars per gallon
            8 dollars per gallon / 8 pints per gallon = 1 dollar per pint

Finally, an example involving cups:


     Sue buys 3 gallons of maple syrup for 96 dollars.
     How much does she pay per cup of syrup?

Here we are given the amount of syrup purchased in gallons and the total amount paid for the syrup, BUT the question requires that we figure out the price per cup.


           96 dollars / 3 gallons = 32 dollars per gallon
           32 dollars per gallon / 16 cups per gallon = 2 dollars per cup

Now you get to try some of these.

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