Lesson video

Hello, my name is Mr. Clasper and today we are going to be looking at ratio and fractions.

Here are some counters.

What is the ratio of blue to yellow? Well, there are three blue counters and five yellow counters, so the ratio is three to five.

What fraction of the counters are blue? Well, there are three blue counters and there are eight counters altogether, so my fraction is 3/8 or three eighths.

What fraction of the counters are yellow? Well, there are five yellow counters and eight counters in total, so my fraction must be 5/8.

What is the difference between the ratio and the fractions? The ratio compares one part to another part, whereas our fractions compare one part of something to a whole.

Here are some more counters.

What is the ratio of blue to yellow to green? Well, I have three blue, five yellow and two green, so my ratio must be three to five to two.

What fraction of the counters are blue? Well, there are three blue counters and there are now 10 counters altogether, so my fraction must be 3/10.

What fraction of the counters are yellow? Well, there are five yellow counters and there are 10 counters in total.

Therefore, my fraction must be 5/10.

We could also write this as 1/2.

What fraction of the counters are green? There are two green counters, and there are still 10 counters altogether, so my fraction is 2/10.

However, we can simplify this to 1/5.

Here is a question for you to try.

Pause the video to complete your task and click resume once you're finished.

And here are your solutions.

So just take care with one b and c so you can have a fraction of 2/6.

But this would simplify to 1/3 and for part c, 3/6 would simplify to 1/2.

Here is a bar model.

It's split into purple sections and green sections.

What is the ratio of purple to green? Well, there are four purple sections and there are five green sections, so the ratio must be four to five.

What fraction of the bar is green? Well, there are five green sections and there are nine sections altogether, so this must be 5/9.

What is the number of purple sections as a fraction of the number of green sections? Well, if we compare these two bars, we can see that the purple sections is equivalent to 4/5 of the green sections.

What is the number of green sections as a fraction of the number of purple sections? Well, we can see by comparing the diagrams again, that the green section is one and a quarter of the purple sections.

This would be the same as 5/4.

Here is a question for you to try.

Pause the video to complete your task and click resume once you're finished.

And here are your solutions.

So question two a, b and c are quite similar to question one.

For part d, the orange is 3/4 of the blue.

So if we compare the orange to the blue, this means that orange is 3/4 of the blue.

And therefore for e, blue is 4/3 of the orange.

The ratio of red to green apples in a basket is five to seven.

What fraction of the apples are red? Well, five parts of my ratio represent the red apples, and there are 12 parts of my ratio altogether.

Therefore, this must be 5/12.

What fraction of the apples are green? Well, seven parts of my ratio represent green apples, and there are 12 parts to my ratio altogether.

So this must be 7/12.

Here is a question for you to try.

Pause the video to complete your task and click resume once you're finished And here are your solutions.

So for part c, we got an answer of 3/2.

This is because the reds counters represent three shares of our ratio and the purple counters represent two, so therefore we have 3/2.

And likewise for part d, this is the other way around, so we have two as a fraction of three, which would be 2/3.

The ratio of x to y is equal to 11 to 18.

What is x as a fraction of y? Well, x is represented by 11 shares of our ratio, and y is represented by 18 shares of our ratio.

So we need to write 11 as a fraction of 18.

This would give us 11/18.

What is y as a fraction of x? Well, if y is represented by the 18 shares of our ratio, and x is represented by 11 shares of our ratio, then this must mean we need to write 18 as a fraction out of 11.

This would be 18/11.

Here are some questions for you to try.

Pause the video to complete your task and click resume once you're finished.

And here are your solutions.

So for question four, the two represents x and five shares represents y, therefore the fraction of x of y would be 2/5 or two fifths.

And likewise, the fraction of y of x is the reciprocal of this, which will be 5/2.

And if I have a look at question six, for part a, we were asked what the ratio of c to d was.

If d is 5/9 of c, this must mean that c is worth nine shares.

Therefore, the ratio must be five to nine.

And for part b, what fraction is c of d? Well, if c is 5/9 of d, then d must be 9/5 of c.

And that is the end of our lesson.

So we've been learning how to use ratio and fractions together, why not try our exit quiz to show off your skills? I'll hopefully see you soon.