Bar graphs

Bar graphs

L.O. To construct and interpret bar graphs.

When to use a bar graph?

• A bar graph is a graph that uses bars of different lengths to compare data.

• The graph compares different categories.

• The graph shows how many in each category.

Multiple Select

What is wrong with this bar graph?

• It has no title and no label on the vertical axis

• There should be a space between the bars

• The bars should all be the same colour but different widths

• The scale on the vertical axis is wrong.

Data will be given by category and frequency, for example:

• Categories : Flavours of ice cream, types of trees, favourite animals, colours of cars.

• Frequency: Number sold, number of each, number of students who chose it.

Multiple Choice

Which graph shows this data?

Poll

Which flavour crisp is your favourite?

• Ready salted

• Salt and vinegar

• Cheese and onion

Poll

Which is your favourite season?

• Spring

• Summer

• Autumn

• Winter

Draw a bar chart to represent the data collected.

You will need to put number of students up the side . Make sure you use a proper scale.

Put flavours of crisps along the bottom in the first one and seasons along the bottom for the second one.

Don't forget a title, labels for the axes, bars of equal width and a space between the bars.

Reading bar graphs

Look for the category and read off the number on the vertical axis which is at the same height as that bar.

Multiple Choice

How many students take the bus to school?

• 35
• 20
• 10
• 15

Multiple Choice

• Ginger Snap

• Oatmeal Cookie

• Sugar Cookie

Multiple Choice

How many chickens does Nate have on his farm?

• 11

• 12

• 9

• 10

Multiple Choice

How many students' favorite color is blue?

• 11

• 12

• 14

• 17

Multiple Choice

How many more people like purple than red?

• 3

• 5

• 7

• 9