On the whiteboard, I put up the following prompt and have the kids respond. (This prompt is also found within the students' Google Drive folder, as we are using a paperless classroom.)
Draw a line. Now, pretend you need everyone in the class to have a line on their papers that is the EXACT SAME SIZE as your line. Explain how you will tell the others how long to make their line WITHOUT using a ruler.
After students have grappled with sharing measurements without using consistent units, I show them a video clip that explains how the first standardized system of measurement (metric system) came about. The video is less than two minutes, so I show the entire thing at once.
After the video clip, I ask the students to share some of their struggles with explaining distance without being able to reference a unit of measurement. I then ask them to explain WHY they think having a standardized system of measurement is helpful. (This answer can be written in notebooks individually or discussed as shoulder partners, later to be shared as a whole class.)
Note: This activity is used to get my Special Education students thinking about measurement and the standard units we use to communicate measurements to others.
This activity is a conversation starter for the lesson as it serves to provide proof for the necessity of a standard system. They can refer to this activity later in the lesson when the need to cite evidence for an argument. This activity also addresses SP5 (Use mathematical representations to describe and/or support scientific conclusions and design solutions). Students are using numbers and the metric system to represent data in the science classroom.
Now, I give students an opportunity to become familiar with some of the units within the metric system. I put a metric ruler and a meter stick on their tables to be shared as a table group. I ask the kids to make observations using the chart I have provided on the Student Graphic Organizer. After 5 minutes, I will solicit responses from students.
Sketch the meter stick and the ruler (be sure to include and letters or significant numbers).
How many little lines are within one CM?
How many CM are within 1M (or the entire meter stick)?
In 10 cm, how many mm?
Based on your observations, what number do you think is important when using the metric system?
Note: During this time, I am observing student interactions with the tools- can they use them? Have they seen them before, etc? I also am challenging the kids to look deeper. How many mm are in 10cm? How many do you think are in one meter?
After students have had an opportunity to explore the tools and units, I give them a hands on model of the metric system using the SMART board as an interactive tool. I have them complete a chart while observing the board in order to take a few notes and have information for the ELABORATE section of the lesson.
On the board, I have the prefixes (Kilo, Hecto, Deka, Deci, Centi, Milli) and their values underneath in non-numerical order. I ask the students to arrange them in order from LARGEST to smallest. Then, I ask them questions that they answer aloud individually: Which is larger Kilo or centi? What to you notice about the numbers as they get larger (should say something about how they GAIN a zero)? What do you notice about the numbers as they get smaller (lose a zero)?
On their own, with a partner or in their notebooks, students answer the following question:
Why is the metric system important for scientists? Use evidence from today's lesson to help you.