Let’s Learn!

Think About It!

Goal: Know when to skip count.

Here are the carrots the students brought for a game night snack:

$Illustration of carrot sticks.$

How many carrots are there? We will use multiplication to find out. This means we will add together equal groups. Multiplication is like repeated addition. Repeated addition adds the same addend many times. We can also use an array to help us find the answer. An array puts items into rows and columns.

$Description of image in following paragraph$

Illustration of three methods for counting. First, multiplication is illustrated by a box with text How many groups? followed by a times symbol followed by a box that reads How many in each group? An arrow points to the next method labeled repeated addition. The repeated addition is represented by 5 empty underlines separated by addition symbols. A blank underlined space is circled and labeled number in each group. A bracket surrounds all blank spaces from below and is labeled number of groups. Finally, the last method is array and it is represented by 8 blue dots in two columns of 4 dots.

We can also use skip counting to help us multiply. Skip counting is counting up by the same number. We will skip count by 2s. It looks like this:

2, 4, 6, 8, 10, 12, 14, 16, 18, 20

Each number in this skip counting sequence is even. An even number is made up of groups of 2! An odd number does not have groups of 2 in it. We know we can skip count by 2s when we see an even number.

Let’s skip count by 2s to multiply!

Groups of 2

Here are the carrots in equal groups.

$10 carrots in a column in sets of two$

Question:

Can we skip count by 2s?

Array

We have an even number of carrots.

$10 carrots in a column in sets of two with each set circled$

We need to create an array. Each carrot will become a dot. Click $mock yellow show-me button$ to see the array!

Repeated Addition

Each carrot is shown with a dot. This array has 5 rows. It has 2 dots in each row.

$10 green dots in two columns and 5 rows with blank addition sentence for adding 5 numbers below.$

We need a repeated addition sentence. The number of rows is the number of addends. The number in each row is the repeated addend.

Question 1:

How many addends do we need?

Question 2:

What is the repeated addend?

Multiplication

This repeated addition sentence can help us find the total number of carrots.

$10 green dots in two columns and 5 rows with addition sentence 2 + 2 + 2 + 2 + 2 = ? and blank multiplication sentence below.$

We also need a multiplication sentence. The number of rows is the number of groups. The number in each row is the number in each group.

Question 1:

How many groups are there?

Question 2:

How many are in each group?

Skip Counting

We need to find the answer to both sentences.

$10 green dots in two columns and 5 rows with addition sentence 2 + 2 + 2 + 2 + 2 = ? and multiplication sentence 5 x 2 = ? below.$

It is quick and easy to skip count! Let’s skip count by 2s. We can do this by skip counting with each row. Click $mock yellow show-me button$ to skip count!