Hong Kong
Stage 1 - Stage 3

# Create and interpret column or bar graphs

Lesson

Graphs are a visual way of presenting information. They can be really useful as they help us sort and order the information we collect and present it in a clear, concise way. Selecting a good type of graph to display your data is really important and the best type of graph to pick will change depending on the type of information you need to display. Let's run through a few different types of graphs now.

## Bar graphs

Bar graph is a generic name for any graph that displays information using rectangular or cylindrical bars.

#### Example

##### Question 1

The sales (in thousands) of different products are shown in the following horizontal bar graph.

1. Which is the best-selling product?

Product A

A

Product B

B

Product C

C

Product D

D

Product E

E

Product F

F

3. If product B was sold at $\$5050 each, find the revenue generated by product B alone.

## Column graphs

A column graph is the name for a specific type of bar graph that uses vertical bars, so they appear like columns. Column graphs are used to show categories of data that you have counted. In a column graph, the height of the column shows the number of scores. Both the horizontal and vertical axes should be labelled to help explain the information in the graph.

#### Example

##### Question 2

A survey of the preferred sport was done for a group of boys and the results are shown in the bar graph below:

1. How many boys prefer football to other sports?

2. Which is the most popular sport?

Football

A

Tennis

B

Rugby

C

D

Hockey

E
3. How many boys took part in the survey?

##### QUESTION 3

John had $7$7 blue marbles, $4$4 black marbles, $8$8 yellow marbles, $13$13 white marbles, and $6$6 red marbles. Use this information to complete the column graph.