Arrays are objects or pictures arranged into rows and columns. You can use arrays to represent and solve multiplication problems.
This array has 3 rows of dots.
Each row has 4 dots.
You can use these numbers to write a multiplication sentence that matches the array:
Let's try it. Make an array to solve The first number is 4. So, the array will need 4 rows. The second number is 5. So, each row will have 5 dots.
There are 20 dots in total. So, 
