Area With Halves

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Objective

SWBAT understand that a closed figure or space covers area and halves of unit squares can also be counted

Big Idea

Fractions can be used to understand halves of a unit square .

Warm-Up

15 minutes

I saw this really cool figure that was drawn out, but it had some diagonal lines in it and I wondered if I could still find the area of it. I want you guys to take a look at some shapes I have drawn on the board. What do you notice? (accept student responses)

I want you to turn and talk to your elbow partner about how you think you can find the area of these figures.

After students discuss we share some ideas. I make the connection to halves with fractions and how 2 halves equal 1 whole. We practice applying this understanding to the examples on the board. 

Group Work

35 minutes

I have some pretty cool shapes that I made, but there are so many halves on them I am having trouble finding the area of each one. I will need your help today finding the area of these figures!

It is important here that I allow students time to work at their tables to try applying the different tools we’ve learned so far to find area (MP1). I will be looking at who is still counting unit squares 1 by 1, who is dividing their shape up and multiplying and who is using all tools, as needed (MP5). 

Close

5 minutes

You guys got some great practice finding area of irregular shapes. You showed me that you can use unit squares and halves of unit squares to find the total area of irregular shapes. Who would like to share something new they learned today?

Some of your students may need some support in presenting / defending their thinking. It is appropriate to give them sentence frames, because they are still doing the thinking and speaking (using math vocabulary of course).

I always think it is important to allow students opportunities to share their work. They take much more pride in their work when they know it is acknowledged and celebrated by their classmates and teacher.