Video: Introduction to the multiplication symbol

﻿Hello there. My name is Mrs. Behan, and I am a very lucky teacher getting to spend some time with you for this lesson. We are going to do something really clever with our equal groups. But first let's take a look at the practise activity that Miss Dotmanavick asked you to have a go at in the last lesson. This is the challenge that she set. I hope she didn't trick you. Was it true or false? This example was false. There are only two groups of cats, but her expression tells us there are three groups of cats. Can you tell me what the correct expression might have been? If you had said three plus three, you would have been correct. There are just two groups of cats, not three. Here is my example. Have a look. Is it true or false? You might want to pause the video whilst you have to think about it. If you work this out correctly, you will know that it is false. There are three groups of two apples. So I only need to write two plus two plus two. Let's practise counting the groups. One group of two, two groups of two, three groups of two. There are just three groups of two, not four groups of two. So I told you earlier that we are going to do something really clever with our equal groups today. We are going to learn a new and much quicker written way to show our equal groups rather than using lots and lots of addition symbols. I'll show you how to do it, and then maybe you could have a go, too. I had a little rummage around my house to find things that are going to help. Here's what I found. I found some sweets and some bowls. I've split the sweets into equal groups so I don't eat them all in one day. I'll show you. So I wanted to start with these tasty and very special blue sweets. The bowls are helping us to see the number of groups. Can you tell me how many groups there are? How many sweets did I put into each bowl? Let's give them a quick count. One, two, three, four, five, six. Check them carefully, see if they're equal. Let's have a look. Yes, I think I did a good job there. They are both equal. So we can say there are two groups of six and we can write this as six plus six. Now here's the really clever part. This a new way of showing our equal groups. We can also write it like this. And this is called a multiplication expression. Can you say that? A multiplication expression. Let's have a closer look at the way the two expressions are written. What do you notice about the two expressions? You could pause here and have a chat with a grownup or just have a little think to yourself. Did you notice that the two symbols are different? Have a really good look at these symbols. Have you noticed they look very similar? We can use both of these symbols to show groups of objects. We just need to make sure we are very careful when we write them down. It's very important that you write your symbol correctly because it helps us to understand the maths. So we've seen this sentence before. There are two groups of six, but when we look at the multiplication expression, can we work out what each number represents? I wonder what the two means. Where can we see two in the picture? Oh yes, I see. The two represents the number of groups. We have two bowls. The bowls are our groups. The next part will be easy now. Where can we see six in the picture? Have you got it? Yes, we can see six sweets in each group. So the six represents the number in each group. Do you think you can help me with another example? And this time it's with fried eggs. Are the fried eggs your favourite? They certainly are mine. So in this picture, you can see there are four groups of three. What does the four represent? What does the three represent? That's right. The four represents the number of groups and the three represents the number in each group. We can write this as three plus three plus three plus three. Now I just want you to count how many threes there are. Why is that? There are four threes because there are four equal groups. We say there are four threes. We can also write this as a multiplication expression as four times three. So I'll ask you again. Can you work out what the four represents? Say it with me. The four represents the number of groups. What does the three represent? That's the number of eggs in each group. The three represents the number in each group. Well done. So in this picture, we don't have any bowls or sweets. We have vases and flowers. This time our vases are the groups because they are holding the flowers. We can see that there are three groups of five. Let's count the groups together. Follow along using your finger on the screen. Let's go. One group of five, two groups of five, three groups of five. You're getting so good at this now. We can write this as five plus five plus five. Pause the video here and see if you can write a multiplication expression. I'll wait here. Remember, be very careful how you write your multiplication symbol. You don't want it to look like an addition symbol. Did you have a go at it? Let's see if you got it right. We can see that there are three fives. We can also write this is as three times five. The three represents the number of groups. In this picture, that's the vase, isn't it? The five represents the number of flowers in each group. Great job, everybody. So I'm going to set you a little practise task now. Why don't you have a go at making groups to match the expression on the screen? You can see six plus six plus six. Think very carefully about the number of groups and think carefully about the number in each group. You could use plates or pots to make your group. You could draw circles as your group if you want to. And to put inside your groups, you could have a go at using small ties, tea bags, sweets, or even pasta to put in your groups. See if you can write the multiplication sentence, too. And if you're ready for another challenge, get ready. You've been able to see all of the individual objects in each group until now. So I'm going to make it a little trickier. Here are some buckets of water. You can't see the water inside, but each bucket has five litres of water in it. Can you write different expressions to match the picture? You're going to have a go at writing a repeated addition expression and have a go at writing a multiplication expression, thinking very carefully about what each number represents and also the symbols that you write. Have fun and thank you for joining me today. See you next time.

Lesson summary: Introduction to the multiplication symbol

In today's lesson we are going to do something  really clever with our equal groups- using the multiplication symbol.

Maths

Introduction to the multiplication symbol

Video

Lesson summary: Introduction to the multiplication symbol

Browse Oak's lessons: