Teaching mathematics

Bar charts

Bar charts are used to represent categorical data, such as favourite colours, and discrete numerical data, such as the number of children in a group of families.

In a bar chart the height of each bar represents the frequency corresponding to each category (Figure 18).

Figure 18 A bar chart

Activity 12 Reading data from a bar chart

Allow 5 minutes

  1. How many people prefer sci-fi films?
  2. How many people like comedy and romance films?
  3. How many people were asked in this survey?

Discussion

  1. Two people prefer sci-fi films.
  2. There are 21 (10 + 11) people who like comedy and romance films.
  3. A total of 36 people were asked (the sum of the frequencies).