Explore Customary Units of Capacity

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SWBAT determine appropriate unit of measurement with which to measure an items capacity.

Big Idea

The students record the appropriate measurement units in a two-column table.

Whole Class Discussion

15 minutes

To begin the lesson, I review what the students learned the previous day about customary units of length.  I ask, Who remembers the customary units of length that we discussed on yesterday? Student responses:  inch, mile, yard, and feet.  Now, who can put those in order from largest to smallest?  I call on one student to respond.  He responds, "inch, feet, yard, and mile."  I ask the students to give me a thumbs up if they agree with the answer.  All of the students raised their thumbs.   I remind them that we use units of length to measure how long an item is, such as the length of the football field.

Today's lesson is customary units of capacity.  I remind the students that customary units are what we use in the United States.  This aligns with 4.MD.A1 because the students will learn relative sizes of measurement units within one system of units.  

I let the students know that the customary units of capacity that we are discussing today are cups, pints, quarts, and gallons.  I tell the students that capacity means the volume of the container in liquid units, or in other words, how much the container can hold.  To give the students a sense of the capacity of the units, I display each unit of measure on the Smart board (Teaching Tool - Customary Units of Capacity).  I ask, What are some items we can measure with a cup?  Student responses:  sugar and flour.  What about a pint?  Student responses:  water and juice.  The students go on to say that soda can be measured in a quart, and milk and orange juice can be measured in a gallon.

I tell the students that it is important to know the appropriate unit to measure for capacity.  Should I measure the capacity of a swimming pool with a cup?  One student responds, "No, it is too small."  Another student adds, "We should use gallons because gallons are bigger than cups."  I let the students know that we can measure the water in a swimming pool with cups, but it would take a very long time.  It would be more appropriate to measure it with gallons.

I let the students know that they will get more practice identifying the appropriate unit to measure capacity as they work in groups.


Skill Building/Exploration

20 minutes

For this activity, I let the students work as pairs to explore and determine the correct customary unit of capacity to use to measure certain items.  By doing this, it allows the students to hear their classmates thinking on the skill.  

I give each pair a Customary Units of Capacity Activity Sheet.  The students must determine the correct customary unit of capacity to use to measure items found in the chart. The students are required to work together on each item.  As you hear in the Video - Customary Units of Capacity, the students must use reasoning to find their answers.

As they work, I monitor and assess their progression of understanding through questioning. 

1. Is this a large item or a small item?  

2.  What is the most reasonable unit of capacity to use?  

3.  Can you use a different unit of capacity?  How do you know?

As I walk around the classroom, I am questioning the students and looking for common misconceptions among the students.  Any misconceptions are addressed at this point, as well as whole class at the end of the activity.


15 minutes

To close the lesson, I bring the students back together as a whole class.  I feel that it is very important to let the students share their answers as a whole class.  This gives those students who still do not understand another opportunity to learn it.  

I feel that by closing each of my lessons by having students share their work is very important to the success of the lesson.  Students need to see good work samples (Student Work - Units of Capacity), as well as work that may have incorrect information.  More than one student may have had the same misconception. During the closing of the lesson, all misconceptions that were spotted during the group activity will be addressed whole class.

My Observations:

I found that the students could determine the appropriate unit of capacity to use when measuring specific items.  The students knew that they could justify their answer based on the size of the item.  For example, some students said that their parents use a pint of milk for their cereal because they use a big bowl.