Does She Have Enough?

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SWBAT use a table to convert customary units of capacity.

Big Idea

Students can determine capacity by converting measures from one unit to another.


5 minutes

Rationale for teaching with a task:

After I have worked directly with the students on a skill, I like to use a task.  A task gives the students more practice on the skill while working in groups.  Allowing the students to work in groups gives the students different perspectives from their classmates.  Students can learn from each other.  As the students work on a task, I am the facilitator, walking around monitoring and questioning the students to lead them to the solution.

I let the students know that today we will do a task.  I remind the students of the structure and routine of a task.  First, the students will have private work time to think about and plan how to solve the task.  Next, the students will work in groups to explore the concept of the lesson.  Finally, the students will share/analyze/and discuss the task as a whole class.  Each student should have a copy of the task at their desk.  In a previous lesson, the students practiced converting units of capacity from one unit of measure to another.

In today's lesson, the students use their understanding of the relative sizes of measurement units within one system of units (4.MD.A1) to solve the task without direct instruction.  


5 minutes

I present the following task to my students:

My mom is baking cookies for a big sale on Saturday at her bakery.  She only has 2 gallons of milk left at the bakery.  She is worried that she will not have enough milk to bake all of the cookies needed for her Saturday sale.  My mom plans to bake the following cookies:


Milk Needed

6  doz. Chocolate chip cookies

8 cups

2 doz. Sugar cookies

2 pints

5 doz. Butter cookies

2 quarts

3 doz. Raisin cookies

3 pints

4 doz. Oatmeal cookies

6 cups


I give the students about 5 minutes of independent time to read and plan to solve this task (MP1). After the 5 minutes of independent planning, we move to the next phase of group exploration.

Skill Building/Exploration

20 minutes

During the exploration phase, the students work in pairs.  Each group has a copy of the task.  The students must work together to complete all requirements of the task. The students are required to convert units of capacity to find out if the mother has enough milk to bake the desired amount of cookies (4.MD.A1).  During this phase, the students do not receive direct instruction.  In this lesson, they apply skills previously learned.   The students are guided to the conceptual understanding through questioning by their classmates, as well as by me.  The students communicate with each other and agree upon the answer.  This takes discussion, critiquing, and justifying of answers by both students (MP3).  As the groups discuss this task, they must be precise in their communication within their groups using the appropriate math terminology for this skill (MP6).  As I walk around, I am listening for the students to use "talk" that will lead to the answer. 

During this phase, I monitor and assess the students' progression of understanding through questioning.  Possible questions to help lead to the solution are as follows:

1.  What is the task asking you to find?  

2.  Is the same unit of measure used in each type of cookies?

3.  How can you solve this problem?

4.  Did she have enough milk?  Explain how you found your answer. 

 Any groups that finish the assignment early, can go to the computer to practice the skill at the following site until we are ready for the whole group sharing:

My Findings:

The students had a really difficult time with this task.  I knew that it would be a challenge, but I didn't think it would be quite this difficult.  There were 2 pairs of students who got the answer to the task.  The other pairs struggled.  Struggle is good, so I'm not too displeased with the lesson.  Eventually, through questioning, most of the pairs realized that they needed to convert the units to find out if there was enough milk. This is a sample of the student work (Student Work).


15 minutes

During this phase of the lesson, student solution paths are shared.  While the students were working in groups and I was walking around questioning, I identified solution paths to be shared as a whole class for this phase.  

I call groups to the front to share their solutions.  This is a teaching opportunity for the few students who may still not know how to add according to place value.  This part of the lesson is lead by the teacher through asking assessing questions.  The students may also have questions that they would like to ask. 

During this phase, I like to organize the sharing of the solution paths in a strategic manner.   I begin with a group that did an excellent job of converting the units of measurement.  From there, I have a pair of students share the answer to the question, "Did she have enough milk?"   Last, the students tell me if mom had any milk left.    

I feel that this is a well rounded lesson on how to convert units of measure in a real-world situation.  By allowing the students to solve a task, it holds the students accountable for their own learning.  They have been given the tools and resources necessary to accomplish solving the task.



10 minutes

After the share/discuss/analyze phase of the lesson, I close the lesson by having the students do an exit ticket.  This will enable me to see how well the students understood how to convert units of capacity.

The students will receive an Exit Ticket - Units of Capacity to complete their answers.  I will collect these exit tickets to evaluate the students' understanding (Student Work - Exit Ticket and Student Work - Exit Ticket2).  Those students who need remediation will work with me in small group the next day.

Results of the exit ticket:

Correct answers:  7

Incorrect answers:  9

From the results of the exit ticket, I know that we have a lot of work to do.  I will meet with each student individually to discuss their exit ticket so that they can see what they did wrong.  We will continue to practice converting units with our metric units.