1. Relate side lengths with the number of tiles on a side.
Math Unit 4 Lesson 4
Relate side lengths with
the number of tiles on a side.

2. Skip Count! Skip Count By 6s To 60 … Skip Count By 7s To 70 …
Skip Count By 7s To 70 …
Skip Count by 8s to 80 …
Skip Count by 9s to 90 …

3. ★ Products In an Array 5 x 3 3 x 5
On your white board, write two different multiplication sentences that can be used to find the total number of stars ★
5 x 3
3 x 5

4. ★ Products In an Array 4 x 6 6 x 4
On your white board, write two different multiplication sentences that can be used to find the total number of stars ★
4 x 6
6 x 4

5. ★ Products In an Array 7 x 3 3 x 7
On your white board, write two different multiplication sentences that can be used to find the total number of stars ★
7 x 3
3 x 7

6. Count the Square Units How many square units are in the rectangle?

7. Count the Square Units How many square units are in the rectangle?

8. Count the Square Units How many square units are in the rectangle?

9. Count the Square Units How many square units are in the rectangle?

10. Count the Square Units They all have an area of 8 square units!
What do all these rectangles have in common?

11. Problem of the Day
Mara & Ashton use square centimeter tiles to make rectangles. Mara uses 15 tiles. Ashton uses 9 tiles.
Draw what Mara & Ashton’s rectangles might look like.
Whose rectangle has a bigger area? How do you know?
Mara’s rectangle
Ashton’s rectangle
Mara’s rectangle has a bigger area because she used more tiles than Ashton.

12. Concept Development 15 square inches
Form your tiles into a 3 x 5 array.
Push the tiles together to make a rectangle with no gaps or overlaps.
Get out 15 square inch tiles.
Thumbs up when you are ready!
What is the area of your rectangle?

13. Concept Development
Here are two rectangles I made using 15 square inch tiles.
Is the area of these rectangles 15 square inches, too?
How do you know?

14. Concept Development
Rectangle A has an area LARGER than 15 square inches, because there are gaps between the tiles.
Rectangle B has an area SMALLER than 15 square inches, because the tiles overlap.

15. Concept Development
Now, go back to that nice, neat rectangle YOU made and measure across the top of the rectangle in inches.
What is the length of this side of the rectangle?
How many tiles on this side of the rectangle?
Next measure the shorter side of the rectangle in inches.
What is the length of this side?
And how many tiles on this side?
5 in. = 5 tiles
3 in. = 3 tiles

16. Concept Development
Draw the rectangle on your white board or inch grid.
Label the SIDE LENGTHS.
What are the units for the sides?
Label the AREA inside the rectangle.
What is the unit for the area?
Why are the units different for the sides and the area?
We use inches to measure length … like the sides.
We use square inches to measure area … or the flat space a figure takes up.
5 inches
3 inches
15 square inches

17. Problem Set!
Let’s figure it out!