I begin this lesson with a read aloud, "Super Sand Castle Saturday" by Stuart Murphy. I begin with this book because it discusses how to measure a sand castle using spoons. The story keeps the students engaged and brings in real world experiences with measuring.
I then ask the students, “How can you use your pencil as a unit of measure?” I then have them use their pencils to measure their desk, chair, and a bookshelf.
The standard MD.A.2 requires that students measure a longer object using multiple shorter objects end to end. One of the misconceptions of students is that they might forget to lay their measuring unit end to end or forget to align it with the end of the object they are measuring. It is important to remind them that to properly measure an item, they must align their measuring tool with the end of the object and also make sure there are no gaps when they lay the tool end to end (MP6)
After students use their pencil to measure classroom objects, I call them back to the carpet. I then show them a picture of a pencil and two examples of how the pencil was measured (also available as a PPT: Make a Nonstandard Measuring Tool). Read the following problem to the students:
Sid and Alli measure the same pencil. Sid says it is about 4 paper clips long. Alli says it is about 3 paper clips long. Circle the name of the child who measured it correctly.
I guide students to make their own paper clip measuring tool by taping 10 paper clips of one color end to end on a strip of sturdy paper* (see below for more explanation of why making the tool this way helps support student learning). Then children tape 10 more clips of a different color end to end so that there are 20 paper clips in all. I make sure children line up one end of their paper clip with the end of the paper.
*I actually didn't have paperclips available when I taught this lesson, so I had the children use a ten rod instead. This actually worked just as well.
I then have the students work together to measure the length of the smartboard. I make sure to encourage children to place their measuring tools end to end to help then measure. I ask the students:
I then have the students use their measuring tool and measure their desk and chair. I guide them to see that using a measure tool is quicker than having to use individual paper clips or measuring units each time. It is easier to line up the nonstandard measuring tool with the object, and then count the measuring units needed to measure the object.
I can extend their thinking even further by asking them to think about how they might figure out the length in paperclips of the smartboard now that they know the length in the tool they created. Some students will grasp right away that you just count by tens to get the total length (if the smartboard is 4 nonstandard tool lengths long, then it's 40 paperclips long), but some students will need to hear this a few times and see you demonstrate it.
Using a nonstandard measuring tool like this one not only helps children understand that a tool with completed units allows them to measure length quickly, it also begins to help them understand the value of using standard rulers later. (MP6)
For the independent practice portion of this lesson, I assign about 6 or 7 classroom objects that I want students to use their measuring tool to measure. I provide them with paper and a pencil to draw the object and write the number of ten rods used to measure the objects.
In this picture a pair of students are working together to determine how many units long their notebook is.
In this video, this pair of students are working together to measure a table in the classroom.
This pair of students are working together to measure the carpet in the classroom:
To close out the lesson, I have students come to the carpet and share one item that they measured.
This student demonstrated how he put his ten rods end to end to measure a computer monitor in the classroom: