Students will start this lesson by gathering on the carpet. Then I will show them a ruler just to capture their attention, and to see what they know. (Make sure you enlarge the picture below or use a large print of the ruler, so students can see the difference between centimeters and inches.)
Today we will be discussing length. When measuring length, we use tools such as a ruler or a yard stick. I want the students to see the difference between a ruler and a yardstick, so that they are able to choose the appropriate measuring tool.(MP5)
I explain that centimeters are along the top of the ruler (above, and inches are along the bottom of the ruler. We also reviewed each mark between the centimeters on the ruler represent one millimeter (mm). To bring their thoughts deeper into the lesson we compare the pencil to the ruler. I point out the pencil tip is at 4 inches, and the end of the eraser is at 0 inches. So, the length of the pencil shown in the illustration above is 4 inches.
Next, I ask student volunteers to point out where to find centimeters and inches on a ruler. I make reference to the starting point of measuring is always (0). I may model a couple of times, so that students can see a visual representation of how to measure correctly. Once students can determine the appropriate tool and unit, and then measure the object, we will move towards our next activity.
We will be focusing on the following Mathematical Practices in this lesson:
MP.5. Use appropriate tools strategically.
MP.6. Attend to precision.
MP.7. Look for and make use of structure.
In this portion of the lesson, I want my students to be comfortable with understanding inches. I ask students to move into their assigned seats. I give each student some colored tiles and a ruler. I want to observe them matching up the endpoints of the objects being measured with the proper unit marks on the ruler. Some students notice that one colored tile is about one inch long. This will allow them to see how estimation works. It is equally important for students to determine the length of the objects by counting the number of unite spaces on the ruler, it is easier for them to do this after comparing the tiles to inches.
To begin I ask students to place one colored tile on the ruler. I circle the room to make sure that they are matching up their endpoints. Most students match their tiles just fine! I ask students to tell me to correct unit measurement of one tile. 1 inch If one tile is one inch, how many inches would 2 tiles be? 2 inches If students are unable to estimate, I ask them to measure two tiles.
Now that students have a pretty good idea how to measure, I give them an additional 6 minutes to explore a bit. As students are busy exploring, I circle the room to check for understanding.
For instance, I ask students to demonstrate how to measure. How many inches is 3 tiles? How many tiles would it take to make 3 inches?
students are counting tiles, and noticing that the number of tiles counted is the same as the number of inches. Having students make sense of structure is an important skill to help students solve problems more efficiently. (MP7)
For the practice activity, I place students with partners. I find that when measuring, students work better with a partner instead of small groups. In larger groups they tend to be fussy!
Before I set the timer for twenty-minutes I go over what students are expected to do. I tell them that they will be measuring various paths to determine shortest length. (Measure task 1, Measure task 2)
After they have measured each item, they are to record their findings and explain how they determine their answers. I want students to focus on the how and why to be able to share their discoveries during the closing of this lesson. I post the directions in large print on the board to remind students of their expectations for this activity.
As students are working, I walk around and observe, taking anecdotal notes to use as reflection and re-teaching strategies. I notice students are measuring and jotting down their responses, however, they are speaking vague.
It is important when planning your lesson to think about several things: How does this lesson build on students' prior learning? How is it congruent with the unit and curriculum goals? How will I assess that we have met the lesson objectives by the end of the lesson? How have I met the different learning styles of the students? Well I thought it would be best to end this lesson with students sharing their findings.
After students have completed their task, I have them to return to the carpet to share their work. I explained that one student should explain how they determine their answer, while the other student held up a copy of their work. Students’ reflections are the best way to assess the effectiveness of this lesson, and to gain ideas for re-teaching. (What you'd do again; what you'd not do again). I encourage students to ask the following questions? How do you position your object to be measured? How do you know if you were measuring in inches? Explain? Did you use tiles, or a ruler? Why or Why not? Do you start at the end of the ruler or on zero?