# Warm Up.

## Presentation on theme: "Warm Up."— Presentation transcript:

Warm Up

Ten Minute Math Today's Number: 219
Create an expression equal to 219. You must use only SUBTRACTION in each expression. Example: =219 and =219 Describe and write about your strategies.

Select a familiar array from the list created the day before.
Example: Egg Carton What are the dimensions of an Egg Carton? What other ways can you think of to arrange 12 eggs into an array, besides 6 by 2 or 2 by 6? Is there another way to write 6x2? 6 x 2 array of 12 eggs 2 6

Arrays of Twelve Factor 12x1, 1x12
Each of the dimensions of 12 are a factor of 12. That means12 can be divided by each of these numbers with no leftovers. What are the factors of 12? 6x2, 2x6 3x4, 4x3

Factor 1 2 3 4 6 12 Each of the dimensions of 12 are a factor of 12.
As we identify the factors of twelve, write them in order in your math notebook and link the factors that go together to make 12. Do you notice that the dame factors occur twice and when we find one array, we can turn it to be the other?  How many factors of 12 are there? 1 2 3 4 6 12

*Label each array with its dimensions (for example, 6 x4 and 4 x6)
Making Arrays Work with a partner to complete a pair of arrays listed below (Every pair of students should have a different number pair).  You may use your centimeter grid paper, locking cubes or color tiles to model the possible arrays.  When you discover an array, cut it out of grid paper and add it to the construction paper labeled with that number. 15 and and and 64 24 and and and 50 18 and and and 38 29 and and and 72 22 and 66 *Label each array with its dimensions (for example, 6 x4 and 4 x6)

Discussion What are the smallest and largest factors that you found for your numbers? Could there be anything smaller? Larger? Why? Why not? Were there number that you knew wouldn’t work? Why? Why are there no factors between (half of the numbers) and (the number itself)? Example: Between 12 and 24 or 18 and 36?

Closure Review the following terms: factor, multiplication, array, and dimensions.  How are they all relate to arrays.  Create thinking map to display the related terms.  Independent Practice: Complete student activity page 5 in math notebooks or on notebook paper.