4-3 Multiplication with Arrays

4-3 Multiplication with Arrays

by Lea Esteve

​This is an array.

An array is a group of objects ​arranged in rows and columns.

​

Rows go across.

​

​

​

Columns go down.​

​

​Let's try one together......​Pair (shoulder partner) -

​

​

How many rows?

​

​

​How many columns?

Multiple Choice

How many rows?

​

​​How many columns?

• 3 rows

  4 columns

• 4 rows

  4 columns

• 3 rows

  3 columns

• 4 rows

  4 columns

​There are different ways to figure out how many total circles are in this array.

​4 + 4 + 4 =12

You can add up the circles in each row.

4 , 8, 12

You can skip count by 4 three times.

4 8 12

​4

​4

​4

​You can multiply the number of rows by the number in each row.

​ 1. 2. 3. 4.

​1

​2

​3

​Let's try one together......

​Think (on your own) -

How many rows?

How many colums

​Let's try one together......​Pair (shoulder partner) -

How would you write a repeated addition sentence to match this array?

Multiple Choice

Which of the following shows a repeated addition sentence to match this array?

• 4 + 4 + 4 + 4 = 16

• 4 + 4 + 4 = 12

​Let's try one together......​Pair (shoulder partner)

​

How would you write a multiplication equation to match this array?

Multiple Choice

How would you write a multiplication equation to match this array?

• 4 x 4 x 4 x 4 = 16

• 4 x 4 = 16

​Important to remember.....

​The number of rows always goes before the number of columns.

​

​How many rows? How many columns?

​

There are 2 rows of 6 columns. So that means there are 2 groups of 6.

​

When writing a repeated addition sentence, the sentence should show 2 groups of 6.

Multiple Choice

Which of the following repeated addition sentences match this array?

• 6 + 6 + 6 + 6 + 6 + 6 = 12

• 6 + 6 = 12

​Important to remember.....

​The number of rows always goes before the number of columns.

​

​How many rows? How many columns?

​

There are 2 rows of 6 columns. So that means there are 2 groups of 6.

​

When writing a multiplication equation, the equation should show 2 groups of 6. We can replace the words "groups of" with a multiplication symbol.

Multiple Choice

Which of the following multiplication equations match this array?

• 2 x 6 = 12

• 6 x 6 = 12