Planning Conversion

Tuesday 10/28/08

Do-now: Explaining the steps of conversion

The math sentences below are showing the steps in converting an amount of water into cups. At each "=" sign, I have poured some of the water into different units, keeping the total amount the same.

Fill in the explanations of what was poured into what at each step. So, for example, you might fill in something like "I pour the twelve quarts into three gallons" or "I pour the two cups into a pint."
    2 gallons + 3 quarts + 1 pint = 2 gallons + 7 pints
I start with two gallons, three quarts, and a pint full of water. Then, I pour


    2 gallons + 7 pints = 8 quarts + 7 pints
Now, I have two gallons and seven pints full of water. Next, I pour


    8 quarts + 7 pints = 23 pints
Now, I have eight quarts and seven pints full of water. Next, I pour


    23 pints = 46 cups
Now, I have twenty three pints full of water. Next, I pour


Measurement card game: Planning what to convert

As we play the card game today, it will work like what we did yesterday, except that now you need to figure out for yourself what order to do the conversions in. You should write down every step as part of a long math sentence.

You may want to put a box around the units in each step to make it clear to yourself that they belong together. As you get used to using math language in this way your eyes will learn to do this automatically.

We will do the first one together as a class; then we will do the rest one at a time on our own before reviewing them as a class.
  1. Convert four cups and two pints into quarts.






  2. Convert one gallon and six pints into quarts.






  3. Convert ten cups, three pints, and four quarts into gallons.

  4. Convert one pint and two quarts into cups.






  5. Convert eighteen cups into fewer units by converting into larger units whenever you can.






  6. Convert eleven cups, four pints, and four quarts into fewer units by converting into larger units whenever you can.






Planning Conversion Homework

As on yesterday's homework, fill in the units you have at each step, and circle the units that you will be pouring off into other units. Under the pictures, write in the math sentence describing those steps.
  1. Convert two cups and a quart into pints.





  2. Convert a pint and a quart into cups.





  3. Convert four cups and two pints into quarts.





  4. Circle the = sign that is incorrect in this math sentence.

    1 gallons + 2 quarts + 3 pints = 1 gallon + 7 pints = 4 quarts + 7 pints

            = 4 quarts + 14 cups = 2 pints + 14 cups = 18 cups