1. MATHEMATICS Line Graphs

2. Lesson Objectives The aim of this powerpoint is to help you… to learn how to complete, read and interpret simple line graphs Note: Distance-Time graphs will be taught in conjunction with speed (in another module of work) Conversion graphs will be taught in conjunction with real-life graphs (in another module of work)

3. Line Graphs Line graphs are linked to time which is always on the x-axis. The other variable will be on the y-axis. Straight lines join one plot to the next. If the lines are dotted, you can NOT read values off the line in-between plots.

4. Line Graph – Example 1 Kirsty takes the temperature at midday for 7 consecutive days. Here are her results. Temperature, °C 20 15 10 5 0 M Tu W Th F Sa Su x x x x x xx

5. Line Graph – Example 1 Q1. On what day was the temperature at its… a) Highest b) Lowest Q2. Why is the line dotted? Temperature, °C 20 15 10 5 0 M Tu W Th F Sa Su x x x x x xx Ans. Sunday Ans. Thursday Ans. The temperature between the 24 hour (daily) measurements may have gone up and/or down so can’t be read off in-between plots!

6. Line Graph – Example 2 One Saturday, Phil took the temperature at hourly intervals. Here are his results. Plot a suitable line graph to represent his data. Note that there is only an hour between timings. It is unlikely that temperatures would have gone up/down much in-between these times so full (rather than dotted) lines can be used! Time09:0010:0011:0012:00 Temperature (°C)111415

7. Line Graph – Example 2 Step 1: Axes and labels Temperature, °C 20 15 10 5 0 09:00 10:00 11:00 12:00 x x x x Time09:0010:0011:0012:00 Temperature (°C)111415 Step 2: Plots – use small crossesStep 3: Join the plots with straight full lines

8. What next? Print out and read through the notes called Data7. Work through pages 1 to 5 of the MyMaths lesson called Line Graphs and Two Way Tables which can be found at: http://app.mymaths.co.uk/353-resource/line-graphs-and-two-way-tables http://app.mymaths.co.uk/353-resource/line-graphs-and-two-way-tables Answer the tasks that appear throughout the Data7 notes. Now move on to the Data-8 powerpoint