SWBAT use their knowledge of decimals on a number line and apply it to the metric ruler.

Using decimals and finding perimeter and area all while learning about the metric system.

10 minutes

30 minutes

The first slide of the power point shows a ruler measuring in centimeters and a ruler measuring in inches. Ask the students to look at the rulers and decide which one shows centimeters? How do they know? (accept any reasonable answers)

Next, ask them what characteristic does the metric system have that helps you to determine which ruler is metric? **(MP2)**

Are there any benchmarks we can use for references on the metric ruler?

Before using the ruler, be sure there is a clear understanding that the metric system is based upon our number system, the base 10 system. This is why we use decimals to represent our answers. Students may question whether a fraction is a viable answer and this could lead to some healthy discussion about decimal equivalents.

There are two slides that can be used for pure, direct instruction. I like to use this time to model for the students how to measure with a ruler. I think out loud as they watch me. I say “Pencils down, eyes on me”. After measuring out loud with them, there are 4 objects to measure in their notes. Students can check their answers with a partner or this can be done as a whole group discussion.

Next, the students will be completing a roundtable exercise with the Art supply worksheet.

- Everyone answers question 1 simultaneously.
- Papers get passed either clockwise or counter clockwise. Before starting the next problem, the students must check the work on the paper they just received. If the answer is correct, they can start the new problem. If it is wrong, they need to discuss the issue with the person it came from and then start the new problem.
- The papers continue to rotate until all questions are completed.

Go over answers as a whole group to check for accuracy.

Bring the students back to their notes and begin working on the application problem. Again, have the students put their pencils down and watch you work out loud for the first problem. Allow students to work/discuss with their tablemates the remainder of the problems. This is a great time to walk the room and check for understanding. The teacher role changes now to facilitator.

**If time permits, the students can use measuring tapes and the How do you measure up worksheet to practice measuring**

30 minutes

Next, the students will be completing a **roundtable** exercise with the Art supply worksheet.

Go over answers as a whole group to check for accuracy.

Bring the students back their notes and begin working on the application problem. Again, have the students put their pencils down and watch you work out loud for the first problem. Allow students to work/discuss with their tablemates the remainder of the problems. This is a great time to walk the room and check for understanding. The teacher role changes now to facilitator.

10 minutes

Have students reflect or journal about the following questions

- Explain in words how to measure length using the metric system?
- What is the difference between the customary system and the metric system? If you had a choice, which system would you use and why?
- How many millimeters in a centimeter?
- Is it ever better to measure in millimeters than centimeters, why or why not?

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