 day's information is being collected on everything. We have data coming out of our ears. These numbers might be showing us something very meaningful, but who can really tell? This is where bar graphs and pie charts come into play. They are really great for displaying data, helping us to easily make comparisons on our data. In this video, we're going to look at pie charts in a little more detail. Sadly for pie charts, they come under fire from data experts who think they are inferior to bar graphs. They argue that pie charts are only suitable in rare circumstances. Like here, we've used the same dataset for both charts, but in the pie chart, it's very hard to see any difference. Pie charts are only good for showing distributions if there are clear differences between each category. They should only really be used when there are less than six categories. So let's turn this population data into a pie chart. We need to work out what size each sector of the pie is going to be. You should already know that there are 360 degrees in a circle. So we need to share this 360 degrees out amongst our different categories. Asia has the biggest population, so needs the biggest slice. To work out exactly how big, we need to add up all of the values to work out the total population, which gives us 7515 million people in the world, which is actually 7.5 billion. The size of the Asia slice is 4478 out of 7515 as a proportion of the full 360 degrees. Then Africa, Europe and the rest. With your protractor, you can now divide your pie chart up by these degrees. Starting from the vertical, measure 215 degrees clockwise and label this sector Asia, then measure 60 degrees and label it Africa, 35 degrees for Europe and then finishing off the last three. This works as a pie chart. Asia is clearly the biggest, getting smaller until Oceana. Good pie chart practice is to start with the biggest sector, so Asia, and then work away clockwise doing the next biggest Africa than the next biggest Europe and keep going in order of size. It massively helps the viewer. Pie charts often also have the percentage written on them. What percent of the world population does each region contribute? So we go back and turn the populations out of the total world population into a percentage, nearly 60% of all people live in Asia. Can you work out what percentage of people live in each of the other regions? Pause the video, find the percentage and click play when you're ready. Did you get them right? And as with any chart or graph, we need a title. Bar chart would have done just as good of a job, but the pie chart hasn't done too badly here. Sometimes questions might give us a pie chart with a percentage already on, and then they ask us to find what this represents. So we know that 25% of the 1200 travelled by bus, so we just need to find 25% of 1200, which is 300 people, or they could even ask us what angle a sector represents. The cycling sector is 8% of the whole circle, so 8% of 360 is 28.8 degrees. Can you find how many people walked and what angle this is? Pause the video and work it out. Did you get 144 people and 43.2 degrees? Here are some more questions for you to do. Pause video, write them out and click play when you're ready. How did you get on with these questions? That's all there is for pie charts. We need to carefully choose when to use them to make sure that they do actually show differences in the data. Most people find data much easier to understand when it's given to them visually, like with bar graphs and pie charts. If you liked the video, give it a thumbs up and don't forget to subscribe, comment below if you have any questions. Why not check out our Fuse School app as well? Until next time.