Lesson video

Hi am Mrs Dennett.

In this lesson we're going to be dividing a quantity in a ratio.

Tom and Mo sharing 300 pounds in the ratio, five to one how much do they each get? Let's draw a bar model to help us to answer this question using the information given.

Tom has five parts and Mo has one so Tom gets five boxes and Mo gets one box.

In total we're told that they shared 300 pounds.

So the sum of all the parts of the ratio, the sum of all the boxes must be 300 pounds.

We want to find out how much money they each gets.

We can see six equal boxes in total so we share the 300 pounds equally between the six boxes this gives us 50 pounds in each box.

Now we can work out how much Tom gets he has five boxes with 50 pound in each box so 50 times five is 250.

Mo has one box so Mo has 50 pounds and we state our answers Tom gets 250 pounds Mo gets 50 pounds.

At this point you could do a little check to make sure that 250 and 50 pounds makes the total that they were sharing 300 pounds and it does.

In this question a drink of juice is being made from cordial and water in the ratio two to seven.

Emma makes 360 millilitres of juice we have to work out how much water and cordial she uses.

Let's draw a bar model using the information that we've been given.

So we have cordial water in the ratio two to seven.

This means cordial has two boxes and water has seven boxes all of the boxes must be equal in size.

We know that Emma is making 360 millilitres of juice in total this means that the sum of all the boxes must be equal to 360 millilitres.

Let's work out how much cordial and how much water she has to use.

We can see that in total there are nine boxes so we have to share 360 millilitres equally between the nine boxes which gives us forty millilitres in each box.

We can now work out how much cordial and how much water Emma needs to use in her juice.

There are two boxes for cordial and each of them have got 40 millilitres in them.

So we do 40 millilitres times two which gives us 80 millilitres of cordial.

Now let's work out how much water she needs to use we can see that there are seven boxes for water and 40 millilitres in each box so this will give us 40 times seven which is 280 millilitres of water.

At this point we can do a quick check to make sure that 80 millilitres and 280 millilitres adds up to our 360 millilitres of juice in total and it does.

So Emma needs to use 80 millilitres of cordial and 280 millilitres of water to make her juice.

Here are some questions for you to try.

Pause the video to complete the task and restart when you were finished.

Here are the answers.

Did you notice that in the last question there are three parts to the ratio so you would need to draw three bars.

One bar with two boxes, one bar with five boxes and a final bar with one box.

Here is a question for to try.

Pause the video to complete the task and restart when you were finished.

Here is the answer.

You should have shared 300 millilitres equally between the six boxes to get 50 millilitres in each box.

From there, you can work out how much strawberry juice and how much Apple juice is needed.

Here is a question for you to try.

Pause the video complete the task and restart when you were finished.

Here are the answers.

When you draw your bar model you will see there are 20 boxes or 20 parts in total.

So we share the 100 squares equally between these boxes, giving us five squares in each box.

There are 45 red squares and 55 blue squares.

Then we're asked to find the difference which is 55 take away 45 which is 10 more blue squares.

Here are some questions for you to try.

Pause the videos to complete the questions and restart when you were finished.

Here are the answers.

Notice that in question four we're only asked for the number of dancers in the show which is forty nine.

For question five we draw up our model for the width and the length.

The perimeter of 32 includes two lengths and two widths.

We're only interested in one length and one width so we have 32 to get 16 this is the total of one length and one width.

This is divided by eight because there are eight boxes in total.

So 16 divided by eight would give us two centimetres in each box.

We can then find the width which is six centimetres and the length which is 10 centimetres.

Use these to find the area the area of a rectangle is given by a length times width 10 times six is 60 centimetres squared.

That was all for this lesson remember to take the exit quiz before you finish.

Thanks for watching.