Customary Units of Liquid Volume

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Objective

Introduced to liquid volume students will learn how to solve problems involving measurement and conversion of measurements from a larger unit to a smaller unit.

Big Idea

Students will be able to use measuring concepts to understand that larger units can be subdivided int equivalent units using the customary units of liquid volume.

Discussion

20 minutes

I open this lesson with a quick review. On last week we learned how to convert ounces to pounds.  We also, discussed how larger units can be subdivided into smaller units.  Can anyone tell me something new you learned so far about converting?  Students are quick to say that they use addition, and multiplication skills to convert. (MP6)

 At the beginning of the lesson it is alright if students are unable to respond here, I am basically checking for understanding.  Checking for understanding allows me to diagnose student knowledge, and reinforce any skills they may need before the lesson begins.

To bring them deeper into today’s lesson I post a conversion chart.   I point to each row as I explain how many units it takes to make a larger unit.  I want them to understand the relationship between the size of a unit and the number of units needed. Even though, my students are fairly familiar with using conversion charts with other units, I still check to see if they are able to make the connections using liquid volume.

1 cup

   8 fluid ounces

 

1 pint

 

    2 cups

1 quart

 

  2 pints

1 half gallon

 

   2 quarts

1 gallon

 

  4 quarts

 

Teacher:

Ok! I’m going to see how much you remember about pounds and ounces.  How many ounces does it take to make 1 pound?  16ounces   If I give you guys 32 ounces how many pounds would that be?  (2 pounds)  How do you know?  (Because it takes 16 ounces to make one pound, but we need 32 pounds) ( It is the same as 16 X 2, =, 16 + 16 = 32 / 16.) What skills did you use to determine the amount of pounds?  ( addition, multiplication, or division)

At this point students are fluently discussing how to convert ounces and pounds.  I feel comfortable moving them forward.  Great guys! Well today we will be applying the same understanding to determine the measure of liquid volume. 

This lesson will be focusing on the following Mathematical Practices: 

MP.2. Reason abstractly and quantitatively. 

MP.5. Use appropriate tools strategically. 

MP.6. Attend to precision


Visual Estimations

20 minutes

In this section of the lesson students are asked to move into their assigned groups.

Because my students require additional support, I want them to have time exploring liquids and the tools.  It is equally important that they begin to estimate volume.  I show the class two covered containers that are filled to different levels with water. I ask students which container has a greater volume of water.   Exactly how much greater is the volume of water in one container than another?

I listen to how students compare the volumes in the absence of units of measure.  They often say things like “1 ton”, “About an ounce more, “Three cups more.”

As students continue to think of how much more liquid is in one container, I ask them how can we measure the volume of a liquid.

As students are brain storming different ways to measure liquid, I refer them back to the liquid chart.  I give each group a set of measuring tools to begin their own investigation.  It is important for them to see a mental image of how to convert.

 

1 cup

   8 fluid ounces

 

1 pint

 

    2 cups

1 quart

 

  2 pints

1 half gallon

 

   2 quarts

1 gallon

 

  4 quarts

  

Just to make sure they understand the use of the given tools I ask them to complete the following tasks:

Show me the container that says a cup.  Show me the container that says 8 fluid ounces. Place them side by side please.  How are they alike?  Fill the cup with water.  How many cups does it take to fill the container that says 8 fluid ounces? As students are discussing and thinking, I ask them to pour the cup of water into the container that says 8 fluid ounces.  What do you notice?  (They are equivalent)  How many cups does it take to make 8 fluid ounces? (1 cup) 

What if I give you 16 ounces? How many cups will it take to fill 16 ounces?  Some students are still over estimating, so I ask them to fill another cup of water and pour it into the container that is labeled ounces.  They noticed that it took two cups to fill 16 fluid ounces.   Then, I want to determine if they can tell me how many without using the tools.  Who can tell me another way to convert when you don’t have tools?  “By adding”, “Multiplying.”

I ask them to prove it.  I continue probing students to see if they can rely on repeated patterns using pints and cups, quarts and pints, half gallon and two quarts, and gallon and 4 quarts.  When students are comfortable converting on their own, I allow them about 15 minutes or so to practice on their own. 

As students are working, I circle the room to listen to how students are thinking.  I chime in to assist where I am needed. When their time is up, I ask student volunteers to share what they have learned with the rest of the class.

 

On Your Own

20 minutes

Material: Assessment

Because students have explored several different tools to measure, I want to assess what they know so far about measuring. I explain that there will be a mixer of other measuring components that we have already covered, along with today's lesson on liquids. I want to see if you all are understanding the relationship of between units. You know like the number of units needs to relate to the size of the unit. To do this, I want to present word problems as a tool of assessing your understanding. Are you guys ready?

As students are working, I circle the room to check for understanding. For instances;  How do you know? How many ounces does it take to make one pound? What if I had more 33 ounces, how many pounds would that be? Can you demonstrate?