1. Drawing Pie Charts Teach GCSE Maths Rom Com SciFi Crime Other Types of DVDs Borrowed Rom Com Sci.Fi. Crime Other Types of DVDs Borrowed

2. "Certain images and/or photos on this presentation are the copyrighted property of JupiterImages and are being used with permission under license. These images and/or photos may not be copied or downloaded without permission from JupiterImages" © Christine Crisp Drawing Pie Charts

3. The table shows the types of DVD borrowed from a library on one day. To draw a pie chart showing the data, we need to calculate the angle for each slice. Type of DVD Number of DVDs (frequency) Rom Com 6 Science Fiction 10 Crime 13 Other 7 Total Tell your partner if you can see how to find the angles. Ans:Find the total frequency. This is shown by 360  so we can then find the angle for a frequency of 1.

4. Type of DVD Number of DVDs (frequency) Rom Com 6 Science Fiction 10 Crime 13 Other 7 Total 6 + 10 + 13 + 7 = 36 Type of DVD Number of DVDs (frequency) Angle Rom Com 6 Science Fiction 10 Crime 13 Other 7 Total So, the total frequency, 36 is shown by 360 . What size angle shows a frequency of 1 ? Ans: 360 ÷ 36 = 10  We can now find the angles for the slices by multiplying the frequencies by 10. 6  10 = 60  10  10 = 100  13  10 = 130  7  10 = 70  Tip: Always check that the sum of the angles is 360 . 360  36

5. Now we can draw the pie chart. 60  Rom Com Total Other Crime Sci Fi AngleDVD 60  100  130  70  360  36 Frequency 7 13 10 6

6. Now we can draw the pie chart.. 100  60  Rom Com Total Other Crime Sci Fi AngleDVD 60  100  130  70  360  36 Frequency 7 13 10 6

7. Now we can draw the pie chart.. 130  70  Tip: Measure the final angle to check on your accuracy. 60  100 . Rom Com Total Other Crime Sci Fi AngleDVD 60  100  130  70  360  36 Frequency 7 13 10 6

8. Now we can draw the pie chart Rom Com Sci Fi Crime Other 60  100  130  70  Label the slices if room... otherwise write labels outside the circle. Crime DVDs Borrowed Finally, the title ( and, using Excel, I can colour the pie ). Rom Com Total Other Crime Sci Fi AngleDVD 60  100  130  70  360  36 Frequency 7 13 10 6

9.  To find the angles for the Pie Chart SUMMARY sum the frequencies, find the angle, a, that gives a frequency of 1: a = 360  ÷ total frequency multiply each frequency by a to find the angles.  Draw a circle and a line from the centre to the top.  Starting from the line, mark the 1 st angle and draw another line.  Repeat the last step for all but the final frequency. Measure the angle of the final slice and check it is correct. check the sum of the angles is 360 .

10. Exercise A group of 18 children were asked which school sport they liked best. The results are shown in the table. Copy the table and draw and label a pie chart to illustrate the data. Sport Number of Children (frequency) Football 8 Tennis 6 Netball 4

11. Solution: Sport Number of Children (frequency) Football 8 Tennis 6 Netball 4 Sport Number of Children (frequency) Football 8 Tennis 6 Netball 4 18 360  ÷ 18 = 20  8  20 = 160  6  20 = 120  4  20 = 80  360  160  120  80  Favourite School Sport Football Tennis Netball Angle