Lesson Video: Taking Apart | Nagwa Lesson Video: Taking Apart | Nagwa

# Lesson Video: Taking Apart Mathematics • Kindergarten

In this video, we will learn how to count to find how many objects are in one part when we break apart a group of up to 10 objects into two parts.

09:47

### Video Transcript

Taking Apart

In this video, we’re going to learn how to count to find how many objects are in one part when we break apart a group of up to 10 objects into two parts.

This boy is a classroom helper. It’s his job to look after all the pencils on each table in his classroom. And we can also see a pot of 10 pencils. The helper is asking for four pencils. Let’s give him four pencils. We’ll need to take them out of the pot. We’ve given out classroom helper four pencils. How many are left in the pot? Did you count them correctly? There are six pencils left. We had 10 pencils in the pot to begin with. The class monitor took four pencils away and there were six pencils left in the pot. When we take objects away from a group, we’re subtracting. The whole amount or the number of pencils we had to start with was 10. If we break this number apart by taking away four, we’ll have six pencils left in the pot. So we can say that 10 take away four is six.

We could do the same using a cube train or counting blocks. This cube train has been broken apart. How many cubes are there altogether? Let’s count them: one, two, three, four, five, six, seven, eight, nine. This is the whole amount or the amount of cubes we used to make our cube train. We can see that the cube train has been broken apart. Let’s count how many cubes were taken away: one, two, three, four. We had nine cubes to start with; this is the whole amount, and we broke the whole amount apart. We took away four cubes. How many are left? Let’s count. There’s one, two, three, four, five, so we can say nine take away four is five.

In this video, we’re going to practice answering some questions where we need to break apart a group of up to 10 objects. And we’re going to use part–whole models and cube trains to help us count how many objects there are in one part. So let’s try some questions now.

Complete the following. When I take apart nine, I get five and what.

In this question, we’re shown nine apples, and we can see that the group of apples has been taken apart to make two groups. We’re told that one of the parts or one of the groups has five apples, and we have to work out how many apples are in the other part. Let’s record what we know using our part–whole model.

We’re told that there are nine apples. This is the whole amount. We’re told that once the apples have been broken apart, one of the part has five apples and we have to work out how many are in the other part. Let’s count how many apples are in each part. This part has one, two, three, four apples. If this part has four apples, then this part must have five apples. When I take apart nine, I get five and four.

A cube train has eight cubes. If five of them are red, how many green cubes are there?

In this question, we’re shown a cube train with eight cubes. So this is our cube train. And we can see that the cube train has been broken into two parts. We’re told that five of the cubes are red, but we’re not told how many green cubes there are. Let’s write this information in our part–whole model. We know the cube train has eight cubes, and we know the red part has five cubes. Let’s count how many green cubes there are. There’s one, two, three. The green part has three cubes. If a cube train has eight cubes and five of them are red, then three of them must be green.

Chloe has seven dolls. She puts her dolls into two boxes. Complete the following sentence. There are three dolls in one box and what dolls in the other. Are there four, three, or five?

In this question, we’re told that Chloe has seven dolls and she puts her dolls into two boxes. We’re also told that there are three dolls in one box, but we’re not told how many dolls are in the other. We have to choose from three possible answers. Are there four dolls in the other box, three, or five? Let’s use a part–whole model to help us think about the problem.

We know Chloe has seven dolls and there are three in one box, and we’re trying to work out how many dolls there are in the other box. Let’s use the picture of the seven dolls to help us. We can cross out the three dolls that Chloe has already put away in a box. Then we can count the number of dolls that are left. There’s one, two, three, four. Now we can complete the sentence. There are three dolls in one box and four dolls in the other. The missing number is four.

Complete the following sentence. When I take eight apart, I get three and what.

This question is all about breaking apart our cube train. We’re told that our cube train has eight cubes, and we have to break it apart into two parts. We’re told that one of the parts has three cubes, so let’s count out our three cubes: one, two, three. Now we can count the number of cubes in the other part. One, two, three, four, five. Now we can complete the sentence. When I take eight apart, I get three and five. The missing number is five.

Choose two numbers to complete the following sentence. Nine is what and what. And we’re given three numbers to choose from: three, six, and five.

Our model shows nine circles. Let’s shade three of them. One, two, three. We had nine circles, and we shaded three of them orange. Let’s count how many circles are left. One, two, three, four, five, six. We can complete the sentence. Nine is three and six. The two numbers we needed to complete the sentence are three and six.

What have we learned in this video? We have learned how to find how many objects are in one part when we break apart a group of up to 10 objects into two parts.