Grade 3

Beginner

5 min

Lesson 1 of 12

The Power of Equal Groups

Not Started

An introduction to multiplication by looking at groups of objects that have the same amount.

Imagine you are hosting a party and want to give 3 stickers to each of your 6 friends. How can you find out the total number of stickers you need without counting them one by one?

Learning Objectives

1.Identify equal groups in everyday situations
2.Turn repeated addition into a multiplication sentence
3.Calculate the total of equal groups using the multiplication sign $\times$

What Are Equal Groups?

In math, equal groups are sets that have the exact same number of items inside them. Imagine you have 3 boxes, and every single box has 5 toy cars. Because every box has the same amount, we call them equal groups. If one box had 4 cars and the others had 5, they would not be equal! We look for equal groups everywhere: in egg cartons, packs of juice boxes, or even the legs on a group of dogs. Recognizing these groups is the first step to mastering multiplication.

Quick Check

If you have 2 plates and each plate has 4 cookies, are these equal groups?

Check if the number on the first plate matches the number on the second plate.

Answer

Yes, because both plates have the same number of cookies.

Repeated Addition: The Secret Bridge

When we have equal groups, we can find the total by adding the same number over and over. This is called repeated addition. For example, if you have 4 baskets with 2 apples each, you can write:

2 + 2 + 2 + 2 = 8

This tells us that 4 groups of 2 equals 8. It is much faster than counting

1, 2, 3, 4, 5, 6, 7, 8

! Repeated addition is like a bridge that connects the simple addition you already know to the power of multiplication.

You see 3 flower pots. Each pot has 5 flowers. 1. Identify the groups: There are 3 pots. 2. Identify the size: Each pot has 5 flowers. 3. Write the addition: $5 + 5 + 5 = 15$ . 4. The total is 15 flowers.

Quick Check

How would you write the repeated addition for 3 groups of 10?

You need to add the number 10 three times.

Answer

$10 + 10 + 10 = 30$

Writing Your First Multiplication Equation

Multiplication is just a faster way to write repeated addition. We use the multiplication sign

\times

to show we are working with equal groups. A multiplication equation looks like this:

\text{Number of Groups} \times ext{Size of Each Group} = ext{Total}

So, instead of writing

5 + 5 + 5 = 15

, we can simply write

3 \times 5 = 15

. The first number (

3

) tells us how many groups we have, and the second number (

5

) tells us how many are in each group.

A teacher has 4 boxes of crayons. Each box holds 8 crayons. 1. Groups: 4 boxes. 2. Size: 8 crayons per box. 3. Multiplication sentence: $4 \times 8$ . 4. To find the total, add 8 four times: $8 + 8 + 8 + 8 = 32$ . 5. Final Equation: $4 \times 8 = 32$ .

There are 5 spiders on a wall. Each spider has 8 legs. How many legs are there in total? 1. Groups: 5 spiders. 2. Size: 8 legs per spider. 3. Equation: $5 \times 8$ . 4. Solve: $8 + 8 + 8 + 8 + 8 = 40$ . 5. There are 40 legs in total!

Key Takeaways

1Equal groups must have the same number of items in every group.
2Repeated addition is adding the same number multiple times, like $3 + 3 + 3$ .
3A multiplication equation is written as $(\text{groups}) \times (\text{size}) = \text{total}$ .
4The symbol $\times$ means 'groups of'.

Quick Check

Multiple Choice

Which of these shows equal groups?

Multiple Choice

What is the multiplication sentence for $6 + 6 + 6 + 6$ ?

True/False

In the equation $2 \times 5 = 10$ , the number 2 represents the size of each group.

What's Next?

Review Tomorrow

Tomorrow morning, look around your kitchen. Can you find 3 things that come in equal groups? (Hint: Look at eggs, juice packs, or chair legs!)

Practice Activity

Draw 4 circles (groups) and put 3 stars in each circle. Write the repeated addition and the multiplication sentence for your drawing.

Browse

Browse

The Power of Equal Groups

Learning Objectives

What Are Equal Groups?

Repeated Addition: The Secret Bridge

Writing Your First Multiplication Equation

Key Takeaways

Quick Check

What's Next?

The Power of Equal Groups

Learning Objectives

What Are Equal Groups?

Repeated Addition: The Secret Bridge

Writing Your First Multiplication Equation

Key Takeaways

Quick Check

What's Next?