Video: Counting fractions

﻿Hello everyone, my name is Mrs. Dolin, and I'll be teaching you your maths lesson today and it's lesson number 12 on fractions. It is now time to review our challenge question from last time. What number could the arrow be pointing to? Chen thinks that the number is two tenths but Sarah thinks the number is six tenths. Who do you think is correct? Don't forget them Mrs. Chen has asked you to explain your answer. Did you do that? Did you get that Chen is actually correct? But the important part is could you explain why? Your explanation might be slightly different to mine. Sarah can't be correct because six tenths is a larger number on the number line than two tenths. Six tenths would be further away from zero and closer to 10 tenths or one whole. Chen's answer of two tenths is a number that is closer to zero than six tenths. And I can visualise that the arrow is pointing to two tenths. Therefore Chen is correct. What do we see here? We've got a bar model and a number line. What do you notice about them? Well, they've both been divided into five equal parts. So what would our unit fraction be? Well, it will be one fifth. We know, that when we count in unit fractions, they make a non-unit fraction. For example three lots of one fifth, make three fifths. Let's have a go at counting in our units and non-unit fractions using the bar model and number line to help us. Remember to start counting from zero. I will start with unit fractions. Are you ready? Zero, one one fifth, two one fifths, three one fifths, four one fifths, five one fifths. Well done if you were following along at home. Now let's do the same but let's count up using non-unit fractions. Remember we're going to start from zero again. Are you ready? Let's go. Zero, one fifth, two fifths, three fifths, four fifth, five fifths. Well done. Let's do this question together. We've seen this image before haven't we? What do you notice? Well, the whole has been divided into five equal parts. So our unit fraction is one fifth. What can you see now? Well, four parts are shaded. Should we count them using our unit fractions to help? One one fifth, two one fifths, three one fifths, four one fifths. Now shall we use our stem sentence to say it together? The whole has been divided into five equal parts. Four fifths of those parts are shaded. Now, so we have a go at writing our fraction as a number on a number line. Our number line has been divided into five equal parts. So, let's count up the equal parts. We've got one one fifth, two one fifths, three one fifths, four one fifths and five one fifths. Now we're going to count on the number line, starting at zero and stop at the number that matches our fraction. Are you ready? Are you going to stop at the right place? Let's have a go. Zero, one one fifth, two one fifths, three one fifths, four one fifths, that's it. Did you stop at the right point? We can write this fraction as a number, as four fifths. I remember this, do you? We wanted to find out, how tall the plant had grown. How many equal parts has the metre stick been divided into? Well, let's count. One, two, three, four, five, six, seven, eight, nine, 10. The metre stick has been divided into 10 equal parts. So what is our unit fraction? It's one tenths. Now let's see how tall the plant has grown. I wonder what fraction of one metre the plant measures. Let's count. One one tenth, two one tenths, three one tenths, four one tenths, five one tenths, six one tenths, seven one tenths. So let's say our stem sentence together. The plant measures seven tenths of the whole metre. Now let's write the fraction as a number on a number nine. How many equal parts would our number line need? Well, it would be 10 equal parts. Now let's show our fraction on the number line. Can you shout stop, when we reach our fraction. Count up with me and stop when we reach our fraction. Remember to start from zero. Ready? Let's go. Zero, one tenth, two tenths, three tenths, four tenths, five tenths, six tenths, seven tenths. Did you shout, stop? Well done, that's fantastic. Now let's write our fraction seven tenths. We're going to continue to practise our counting in unit and non-unit fractions on a shape and on a number line. So have a look at the shape and have a look at the number line. How many equal parts has the whole been divided into? That's right, nine equal parts. So our unit fraction is one ninth. Let's count up in unit fractions of one ninth. Off we go. One one ninth, two one ninth, three one ninths, four one ninths, five one ninths, six one ninths, seven one ninths, eight one ninths, nine one ninths. Well done. Now let's count up in non-unit fractions. Remember to start from zero. Are you ready? Zero, one ninth, two ninths, three ninths, four ninths, five ninths, six ninths, seven ninths, eight ninths, nine ninths. Well done for counting along at home. Can you spot the number, four ninths on your number line? Can you point to where it is? Where would you point to? Well done if you're pointing to this point here on the number line, that shows four ninths. Let's have a go at counting up and down with our eggs. How many equal parts has the egg box been divided into? How many equal parts are there on the number line? Well, they both have 12 equal parts. So our unit fraction is one twelfth. Let's count up in unit fractions in twelfths. Count along with me and don't forget to start on zero. Off we go. Zero, one one twelfth, two one twelfths, three one twelfths, four one twelfths, five one twelfths, six one twelfths, seven one twelfths, eight one twelfths, nine one twelfths, 10 one twelfths, 11 one twelfths, 12 one twelfths. Well done for counting along at home. Now let's count up in non-unit fractions. Remember to start from zero. Are you ready? Let's go. Zero, one twelfth, two twelfths, three twelfths, four twelfths, five twelfths, six twelfths, seven twelfths, eight twelfths, nine twelfths, 10 twelfths, 11 twelfths, 12 twelfths. Well done. Can you point to the number, 11 twelfths on the number line? Where would it go? Where is 11 twelfths? Well done if you're pointing to here, 11 twelfths. Now let's look at our practise activity. Can you show this fraction using a number line? So, you might have to ask the adult to help you with drawing a number line. Remember to use a ruler and you could have it that one centimetre equals one equal parts. When representing this fraction on a number line, what number are you going to have to stop counting up to on the number line? What point will you stop at? Remember it has to be accurate, your arrow can't be spaces in between, it has to be pointing exactly at the fraction that this drawing is showing. Let's have a look at your next practise activity. Here is a window. How many panes of glass can you see? Oh, what happened to the glass in some of the panes? Well, some of them have been broken. What fraction of the whole window will need new window panes? Can you show this fraction using a number line? Can you write the fraction as well. I wonder as a tap activity, what fraction of the window pane did not break? How this fraction look different? Can you have a go representing this number on a number line? How would it look different? Thank you for joining us today and see you soon.

Lesson summary: Counting fractions

In this lesson, we build fluency of counting fractions using a range of representations.

Maths

Y4 Maths

Key Stage 2

Year 4

Counting fractions

Taking fractions further

UNIT

Building wholes

Building and comparing wholes

Building and comparing wholes from different unit fractions

More building and comparing wholes from different unit fractions

Representing non-unit fractions

More representing non-unit fractions

Non-unit fractions in different contexts

Fractions equivalent to one whole

Visualising non-unit fractions

Fractions on a numberline

More fractions on a numberline

Repeated addition of unit fractions

More repeated addition of unit fractions

Fractions equal to one whole

Beginning to compare non-unit fractions

Using Equivalence to 1 to Compare Non-Unit Fractions

Use Several Methods to Compare Two Fractions with the Same Denominator

Can We Easily Compare Two Fractions With the Same Denominator?

Order Several Non-Unit Fractions with the Same Denominator and Apply this Understanding

What do you notice when comparing two unit fractions using an area model?

What do you notice when comparing two unit fractions on a numberline?

Use What You Know to Compare Two Non-Unit Fractions With the Same Numerator

Counting fractions

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Lesson summary: Counting fractions

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