Multiplication: Using Arrays

What is Array Multiplication? An arrangement of objects into rows and columns that form a rectangle. All rows must be filled. Each row and column has the same number of objects. Multiplication arrays are blocks of dots or other shapes that show any multiplication problem visually. By arranging multiplication arrays using groups, we can understand what multiplication is: number of items in a number of groups.

How to arrange the array 4 X 5 = The first number in the multiplication fact is represented by a row of symbols across the top. The second number in the multiplication fact is displayed downward from the first symbol in the top row.

Click here to return

Arrangement continued Once you have completed your foundation, (click here to see what your foundation should look like) Fill in/complete the rectangle (click here to see what the complete rectangle should look like). Count all the symbols in the rectangle and POOF you have your answer.

Click here to return

“Array Ways” There are four ways that an array may be arranged. 4 –by-1 array Click to view Click to view 4- by-2 array 2-by-4 array Click to view 1-by- 4 array Click to view

return

return

return

return

Example REMEMBER: Each column stands for 1 package (or six -pack). Louise buys four packages of juice boxes. Each package has six juice boxes in it and is called a “six- pack.” Show the four packages as an array. Think: there are 4 groups ( 4 packages of juice boxes). Each group has the same number of boxes (6) in it. Draw a 4 –by- 6 array to show the 4 groups. REMEMBER: Each column stands for 1 package (or six -pack).

Let’s Practice If there are seven tables and five chairs per table, how many chairs are there in all?

Lets check. Well how many tables are there (they represent the columns)? Seven Now how many chairs at each table (they are represented by the rows)? Five Once everything is filled in, you are counting five chairs at each of the seven tables!! Got It??!!

YES!! 7 return

return 3 On the right track!!

return 21 Great!!

Now let’s solve the problem for a given array!! __click____ X _click_____ = __click____

Great Job!! For additional practice, using an interactive website; please visit: http://www.haelmedia.com/OnlineActivities_txh/mc_txh3_002.html