Arrays: Adding in Rows and Columns
Grade 2 Mathematics Learning to count objects in rectangular arrangements
What is an Array?
Objects arranged in equal rows Objects arranged in equal columns Same number of items in each row Makes counting easier and faster
Let's Make an Array!
Use your counting bears Make 2 rows with 3 bears in each row Count the total number of bears Write the addition equation: 3 + 3 = 6
Counting by Rows
Start with the first row Count all objects in that row Move to the next row Add the numbers together
Rows vs Columns
{"left":"Rows go left to right →\nLike reading a book\nCount across","right":"Columns go up and down ↕\nLike a tall building\nCount up or down"}
Can You Count This Array?
Look at the array of flowers How many rows do you see? How many flowers in each row? What addition equation can you write?
Create Your Own Array
Choose your favorite manipulative Make an array with 3 rows Put 5 objects in each row Draw your array on paper Write the addition equation
Arrays Help Us Add Faster!
Arrays make equal groups We can add the same number multiple times Arrays help us see patterns Practice makes us better at math!