Lesson video

Hello, I'm Mr. Tazzyman.

Today we are gonna be learning about statistics 'cause this unit is all about them.

Statistics we see in lots of different places, so it's a really important unit because it will help us to understand the world around us.

Okay, let's get started.

Here's the outcome for the lesson then.

By the end of it, we want you to be able to say, "I can construct pie charts using angles, fractions, and percentages." The key words today are pie, chart and sector.

I'm gonna say them and I want you to repeat them back to me.

I'll say my turn, say the word and then I'll say your turn and you can say it back.

Ready? My turn, pie chart.

Your turn.

My turn, sector.

Your turn.

A pie chart is a circular graph where sectors represent different groups in proportion to each other.

You can see a pie chart just underneath that definition there.

A sector is a part or pie slice, part of a pie chart, and there are two sectors in the pie chart shown there.

One sector is bigger than the other.

Here's the outline then.

We're gonna begin by using angles to construct pie charts.

Then we'll move on to using fractions and percentages.

In this lesson, you're gonna meet Sofia, Izzy, and Jacob.

They're gonna be giving us some prompts about the maths, discussing some of the learning, and they'd also give us some questions as well.

Izzy, Jacob and Sofia are making a pie chart.

We've got dragonfly nymph and a tadpole.

We were pond dipping and found 36 creatures, wow.

"We found dragon fly nymphs, tadpoles and water beetles." "My favourite were the water snails.

They were very cute." I agree, Izzy.

Izzy, Jacob, and Sofia decide to make a pie chart.

We need to work out how to create a pie chart using our table.

There are 360 degrees in a circle altogether, 360 degrees divided by 36 is equal to 10 degrees, and remember they'd found 36 different creatures.

We're dividing by 36 because there were 36 creatures found that our pond dip.

When we create our pie chart, each little creature will be represented by 10 degrees.

They start with dragonfly nymphs.

"We found four dragonfly nymphs altogether" "10 degrees multiplied by four is equal to 40 degrees.

The sector needs to measure 40 degrees." "I'm gonna use a protractor to measure this." You can see they've lined up the starting line with zero and then they'll count round to 40.

"I'll draw a line to make a sector of 40 degrees.

I'll make a mark at 40 degrees and draw a line from the centre of the circle." There we go, done.

"You've drawn a radius, Izzy.

A line from the centre to the circumference of the circle." They add a sector representing tadpoles.

"We found 13 tadpoles altogether." "10 degrees multiplied by 13 is equal to 130 degrees.

The sector needs to measure 130 degrees." "I'm going to use a protractor", says Izzy.

Notice that she puts the zero in a different place this time, not from the starting line, but from the line that had just been drawn at 40 degrees.

I draw a line to make a sector of 130 degrees.

I'll make a mark at 130 degrees and draw a line from the centre of the circle.

They add a sector representing water beetles.

"We found five water beetles altogether." "10 degrees multiplied by five is equal to 50 degrees.

The sector needs to measure 50 degrees." "I'm going to use a protractor.

I'll draw a line to make a sector of 50 degrees." They add a sector representing water boatman.

"We found eight water boatman altogether." Wow.

"10 degrees multiplied by eight is equal to 80 degrees.

The sector needs to measure 80 degrees." "I'm going to use a protractor.

I'll draw a line to make a sector of 80 degrees." They check the sector representing water snails.

"We found six water snails, 10 degrees multiplied by six is equal to 60 degrees." "That's great, the sector measures exactly 60 degrees." Phew, and great measuring you two.

Let's complete our pie chart.

They write in the numbers and they use colours to distinguish between the different sectors.

Now let's add a title to explain what the pie chart shows.

Pie charts showing creatures found during pond dipping.

We can add a key to help people interpret the pie chart, and you can see they've put the colours down there with the type of creature that the colour represents.

Okay, let's check your understanding now.

Izzy, Jacob and Sofia Complete another pond dip.

This time we found 18 creatures.

How could you work out how many degrees would be needed to represent each creature? Pause the video and have a think about that.

Welcome back.

Well, Izzy starts by doing 360 degrees divided by 18, which is equal to 20 degrees, so we know that each creature represents 20 degrees in our pie chart.

Each creature should be represented by 20 degrees, as Izzy has said there.

Knowing that it's now time for your first task.

You've got to create a pie chart representing the pond dip.

Remember, there are 18 creatures in total.

Use a protractor to measure accurately.

Complete the key to help people interpret the pie chart.

Pause the video here and have a go at creating that pie chart.

I'll be back in a little while to show you what it should have looked like.

Good luck.

Welcome back, here's one possible solution then.

There were two dragon fly nymphs, which is equal to 40 degrees.

There were six tadpoles, which is equal to 120 degrees.

There were three water beetles, which is equal to 60 degrees.

There were two water boatman, which is equal to 40 degrees.

There were five water snails, which is equal to 100 degrees.

Here's the key, and there are the colours.

Your pie chart might have looked something like this.

Of course, you've needed to add in a title too.

We've chosen "Pie chart showing creatures found during pond dipping." Your completed pie chart should look something like this.

Pause the video here if you need some extra time to compare what you've produced to what's on screen.

Welcome back.

It's time for the second part of the lesson, using fractions and percentages.

Pie charts can be divided into different sized parts.

One 10th of the pie chart is shaded.

This is the same as 10%.

There are 360 degrees in a circle all together.

360 degrees divided by 10 is equal to 36 degrees.

One 10th of the pie chart, or 10%, is equal to 36 degrees.

One fifth of the pie chart is shaded.

Hmm, I wonder how these numbers will change if it's one fifth? Well, this is the same as 20%.

There are 360 degrees in a circle altogether, 360 degrees divided by five is equal to 72 degrees.

One fifth of the pie chart, or 20%, is equal to 72 degrees.

One quarter of the pie chart is shaded, so this time we are using a quarter.

I wonder how that will change things? Well, this is the same as 25%.

There are 360 degrees in a circle altogether.

360 degrees divided by four is equal to 90 degrees.

That's sometimes known as a right angle.

One quarter of the pie chart or 25% is equal to 90 degrees.

I wonder what size part that is.

Looks a lot smaller than some of the ones we've seen already.

One 20th or 5/100ths of the pie chart is shaded.

This is the same as 5%.

There are 360 degrees in a circle altogether.

360 degrees divided by 20 is equal to 18 degrees.

1/20th of the pie chart, or 5%, is equal to 18 degrees.

Wow, even smaller again.

1/100th of the pie chart is shaded.

This is the same as 1%.

There are 360 degrees in a circle altogether.

360 degrees divided by 100 is equal to 3.

6 degrees.

1/100th of the pie chart, or 1%, is equal to 3.

6 degrees.

Izzy, Jacob and Sofia create a pie chart.

"We investigated the 60 trees in our local park to find out what type they were." "15 of the 60 trees are field maples.

This means 15/60ths are field maples".

"I can simplify the fraction by dividing the denominator and numerator by 15." 15/60ths is equal to one quarter.

25% is also equal to one quarter.

360 degrees divided by four is equal to 90 degrees.

I'm going to create this sector.

Puts the protractor down, making sure that zero is on the starting line and draws in a sector that's 90 degrees.

20 of the 60 trees are hazels.

This means 20/60ths are hazels.

I can simplify the fraction by dividing the denominator en numerator by 20.

20/60ths is equal to one third to find one third divide by three.

360 degrees divided by three is equal to 120 degrees.

I'm going to create this sector.

Good use of the protractor again.

10 of the 60 trees are holly trees, which is equal to 10/60th or one-sixths.

To find one-sixths divide by six.

360 degrees divided by six is equal to 60 degrees.

Time to get that protractor out again.

I'm going to create this sector.

The protractor is laid down again, making sure that zero is on the new starting line and 60 degrees is marked in.

There's a diameter, a line going across the circle and through the centre.

You can see it there.

Let's check your understanding then, so far.

What percentage of the trees are oak trees? Six of the 60 trees are oak trees, work out what percentage of the total are oak trees? You might need to work out the fraction of trees that are oak trees first.

Pause the video and have a go at that.

Welcome back.

6/60ths of the trees are oak trees.

Six and 60 are both divisible by six.

6/60ths is equal to 1/10th.

1/10th is equal to 10%.

Did you manage to get that? I hope so.

Next bit to check your understanding.

Can you add oak trees to the pie chart? 10% of the trees are oak trees.

How would this sector be added to the pie chart? Have a think.

Pause the video and give it a go.

Welcome back.

To find 10% divide by 10.

360 degrees divided by 10 is equal to 36 degrees.

Time to get the protractor out then.

You put it on the new starting line, making sure zero's lined up.

Find 36 degrees and write in the new sector for oak.

Izzy says, "That's perfect because 15% of the trees were older, which makes up the last sector." There it is.

Okay, it's time for your second practise task now.

You need to create a pie chart representing this minibeast hunt.

Start by counting the total number of creatures.

Work out the fraction of the hole for each type of minibeast and work out the number of degrees, use a protractor to measure accurately.

Here's the pie chart template.

A pie chart showing creatures found during a minibeast hunt.

Complete the key to help people interpret the pie chart.

Pause the video here and have a go at that.

Enjoy.

Welcome back.

Here's one possible answer then.

There are 40 creatures altogether, eight of the minibeasts are spiders.

Eight out of 40 is equal to one-fifth or 20%.

10 out of 40 is equal to one-quarter or 25%, for the woodlouse this makes up 25%.

2/40th or 1/20th or 5% for centipedes.

4/40ths or 1/10th or 10% for snails and 16/40ths or two fifths or 40% for beetles.

Now we know the quantity of each type of minibeast and the proportion of it as well.

So your pie chart might have looked like this.

Spiders at 20%, woodlouse 25%, centipedes 5%, snails 10%, and beetles 40%.

To find 20% divide by 5, 360 degrees divided by five is equal to 72 degrees.

That's how the spiders sector was found.

To find 40% multiply 72 degrees by two, 72 degrees by two is equal to 144.

That's how the beetles were found.

The percentages add together to equal 100% or one whole.

Pause the video here if you need more time to compare what you've produced with what's on screen.

Let's summarise today's lesson then.

A pie chart is another way of presenting data representing parts of a whole.

Pie charts can be constructed using knowledge of angles and fractions.

A protractor is used to accurately measure each angle.

I really enjoyed learning that today.

I hope you did as well.

My name is Mr. Tazzyman and maybe I'll see you again soon.

Bye for now.