Rectangular Arrays

Present pictures of rectangular arrays. Ask the students the following questions (Slide 5):
How would you describe the rectangles?
Is one of the arrays shaped like a square?
Why do you think the array with 9 objects makes the shape of the square?
If you want a long or wide rectangular array, should you have more rows or more columns?
If you want a tall and skinny or narrow rectangular array, which should you have more rows or columns?
If you want to create a square array, what should your rows and columns look like?

Students will work with a partner to create rectangular arrays. Each partnership will share a set of dice and tiles. Each student should have their own paper to record their own arrays. The picture of the game directions is hyperlinked to the resource. The students will play this game for 15 minutes (Slide 6).
Game: https://www.k-5mathteachingresources.com/support-files/roll-a-rectangular-array.pdf

As students play, possible questions:
How would you describe your array?
How many rows do you have?
How many columns do you have? 
How many tiles do you have altogether? 
How could this arrangement of tiles help you determine the total number of tiles you have without having to count every tile?
How do you think arrays could help you count more efficiently? Do you have to have an even number of objects to make an array? Use the tiles to prove your argument.

Display 3 pieces of student work. As you display each piece of student work, ask the students:
What do you notice? What do you wonder?
If students do not use appropriate terms such as an array, rows, and columns in their description, restate their response using the correct vocabulary.