Lesson Video: Identifying Odd and Even Numbers: Pairing or Grouping Mathematics • 2nd Grade

Video Transcript

Identifying Odd and Even Numbers: Pairing or Grouping

In this video, we will learn how to decide if a number up to 20 is even or odd by investigating whether you can divide it into two equal groups or into groups of two.

These children are investigating odd and even numbers. They’re investigating the number seven. To decide whether this number is odd or even, they’re investigating whether or not seven children can make two equal groups. The first group has three children, and the second group has three children. But this girl isn’t in either group. We can’t place her in any of the groups because then one group would have four children, and the other group would have three. So, the groups wouldn’t be equal. If we can divide a number into two equal groups, this would be an even number. But if there’s a remainder, this means this is an odd number. So, the number seven is an odd number.

What would happen if there was one more child? Now, there are eight children. Now, we have two equal groups. There are four children in each group. So, eight is an even number.

So far, we’ve learned that if you can divide a number into two equal groups with nothing left over, it’s an even number. If we try to divide a number into two equal groups and there is a remainder, we know it’s an odd number. Let’s investigate some more numbers to decide whether they’re odd or even.

Here is a group of six people. Can we split them into two groups with the same number of people in each group?

In this question, we’re shown a picture of a group of six people. The question asks us whether or not we can split this group of people into two groups, with each group having the same number of people in it. This question is all about investigating odd and even numbers. If we can split the people into two equal groups, we know that six is an even number. And if we can’t, we know it’s an odd number. So, can we split six people into two equal groups? Yes, we can. Six is an even number.

Is the number of cats odd or even?

In this question, we’re shown a number of cats. We have to decide if this number is odd or even. So, the first thing we need to do is count the number of cats. Let’s use some cubes to help us count. One, two, three, four, five, six, seven, eight, nine. Now we know there are nine cats. We need to decide whether nine is an odd or even number. One way we can investigate whether a number is odd or even is to divide our number or our objects into two equal groups because even numbers can be divided into equal groups.

If we divide our nine bricks into two groups, both groups will have four bricks, but there’s one left over. This means the number nine is an odd number. We counted nine cats and modeled this number using nine cubes. And to decide whether nine was odd or even, we tried to divide the cubes into two equal groups, but we couldn’t. There was one cube left over. We know this means that nine is an odd number. The number of cats is odd.

So far, we’ve learned that we can tell if a number is odd or even by seeing if we can divide it into two equal groups with nothing left over. If we can, we know the number is even. If we can’t, we know the number is odd. Another way we can decide if a number is odd or even is by making pairs. If you can make pairs, then the number is even. If you make pairs and there’s one left over, then the number is odd. Let’s investigate some more numbers now and decide whether they’re odd or even by making pairs.

Is eight even or odd?

In this question, we’re shown eight squares, and we have to decide if the number eight is even or odd. One way to decide whether a number is even or odd is to see if you can make pairs. Let’s make pairs of cubes. Here’s one, two. We’ve made one pair. Three, four. Now, we’ve got two pairs. Five, six. Now, we’ve got three pairs. Seven, eight. We’ve made four pairs. So, eight is an even number. We know that if we can make pairs, the number is even. And if there’s one left over, we know the number is odd. Eight is an even number.

Is 13 even or odd?

In this question, we have to decide if the number 13 is even or odd. We can model the number 13 using some 10 frames. 10 and three more makes 13. To help us decide if this is an odd or even number, we could see if we can make pairs of counters. If we can, we know that 13 is an even number. If not, and as a counter left over, we know 13 is an odd number.

So, let’s see if we can make pairs. Here’s one, here’s another pair, here’s another pair, and two more pairs. So far, we’ve been able to divide our 10 counters into five pairs. So, we know that 10 is an even number. Another pair makes 12. And we’ve got one counter left over. So, we can’t make this into a pair. So, the number 13 is an odd number. We modeled the number using 10 frames and then we make pairs of counters. There was one counter left over. So, we know that 13 is an odd number.

What have we learned in this video? We learned how to decide if a number is odd or even by grouping objects or making pairs. We learned that even numbers can be split into two equal groups or pairs. If we try to split odd numbers into two equal groups or pairs, there’s always one left over.