# What is a Line Graph?

What is a line graph? For kids

A line graph is used to represent information that changes over time. A line graph is plotted with joined points to create a straight line. Children begin to learn about line graphs in Years 4 and 5 before making their own in Year 6.

Line graphs help with representing a value over time. Graphs are ideal for adding a visual representation to statistical data. They are brilliant for plotting data that couldn’t be shown in any other chart; for example, ‘How many school lunches are eaten each day?’ This question couldn’t be well represented in a pie or bar chart as the scale is overtime.

What are the five parts of a line graph?

• The Y-Axis – In a line graph, two axes represent two data types. The Y-axis is vertical (upwards). This is typically the axis that shows a measurement; it always starts at 0. All sizes must be split equally down the axis. For example, the number of school lunches would be measured here.
• The X-Axis – The X-axis is the horizontal (across/flat) line that often represents the names, dates, or times measured in the line graph. For example, the dates/ period of school lunches would be counted here.
• The Title – This is the first thing a reader will see when they look at your graph. It needs to be short, to the point, and answer exactly what the chart is about. For example, a title for the school lunch graph could be ‘Number of hot school lunches sold p/day: From the 10th of February to 10th of March‘.
• The Source and Data – Where did the information come from? What data have you collected to plot in your graph? Is there more than one set of data to represent? These questions are important to answer in your line graph. Make sure to credit whoever the source of information was from. If you need to show more than one type of data, for example, ‘Hot school lunches about 2018’, then you could plot two lines on your graph in different colors; it’s important to write a key on the side of your chart to show the reader what each line represents.
• The Legend – This is vital for showing the reader what each line means. Write a short sentence explaining each axis, e.g., ‘Number of Lunches sold (in hundredths)’ for the Y-axis and ‘Date’ for the X-Axis.