Minds On

Reviewing types of data: discrete and continuous

When we inquire with diverse questions, we receive diverse kinds of data. Each type of data can be graphed in various ways, or even combined on the same graph.

Data can be divided into two main types. Press ‘Continuous’ and ‘Discrete’ to explore definitions.

Continuous data can change over time and be measured with values that exist between whole numbers (decimals and fractions). Continuous data answers the question, “What is changing?”

Discrete data is represented by categories. These are items that can be counted. The values can only be whole numbers with no fractional part. Discrete data answers the question, “How many?”

Student Tips

Continuous or discrete?

Unsure whether the data you’re examining is continuous or discrete? Ask yourself whether something being measured (continuous data) or counted (discrete data).

Brainstorm

Examine the graphs

Examine the following two graphs below. Answer the following questions about each graph:

  • What do you notice about how the information is presented?
  • Is the data continuous or discrete? How do you know?

Throughout this learning activity, you can record your ideas digitally, orally, or in print.


Action

Representing data

Data is important for understanding the world around us. For example, data helps various levels of government make decisions. It’s important to represent data in a way that will help people understand the story it tells.

Activity 1: Different ways to represent the same data

In the following table and graphs, the same data is represented. Investigate these representations.

Press ‘Population’ for a helpful definition.

Population is the total set of subjects (e.g., individuals, objects, species) that fit a particular description. An example of a population is “salmon in Lake Ontario.”

Data table

This data table depicts the fishing of selected species in Canada, 2015.

Total Fish Harvest, Selected Species, Canada, 2015
Species Number harvested

Bass

20,370,825

Perch

23,536,400

Pike

25,114,724

Trout

38,537,379

Walleye

50,507,141

Other

36,248,834

Bar graph

Check out how the data from the data table is used to make the following bar graph:

Circle graph

Explore how the same data is used to make the following circle graph:

Brainstorm

Time to compare!

Compare the data table, the bar graph, and the circle graph.

Complete Comparison: Data Representations in your notebook or use the following fillable and printable document. If you prefer, use another method to record your ideas.

Comparison: Data Representations
Compare the data table, bar graph, and circle graph to answer the following questions.

What is the same in each of these data representations?

Do these graphs represent discrete or continuous data? Hint: Ask yourself whether something is being measured (continuous data) or counted (discrete data).

Which representation would help you answer the following question: Which two species of fish make up nearly half of the total fish harvested in Canada?

How do percentages help us to analyze the distribution of data?

Press the ‘Activity’ button to access Comparison: Data Representations. 

Activity 2: Converting data into percentages

Press ‘Frequency table’ for a helpful definition.

A frequency table organizes data into categories and shows the number of occurrences for each category.

Brainstorm

Examine the frequency table

The frequency table below gives information about the number of Ontarians in various age groups.

  • Describe any relationships that you notice in the data.
  • How could we adjust the information in the table to further examine the relationships in the data?
Ontario Census Profile, 2016
Age group Number (frequency)

0-14

2,207,970

15-29

2,580,410

30-44

2,579,116

45-59

2,983,190

60-74

2,112,535

75-89

872,665

90+

112,609

Total

13,448,495

Student Tips

Use percentages to compare!

Did you find it difficult to compare the populations in the various age groups?

When you’re examining categories of a large population, it is easier to compare them by using percentages or relative amounts instead of exact quantities.

Press ‘Percent’ to review the definition.

Percent is a ratio expressed using the percent symbol: %. Percent means “out of a hundred.”

  • For example, 30% means “30 out of 100.”

A percent can be represented by a fraction with a denominator of 100.

  • For example, 30% = 30/100.

Calculating percent

To convert large sets of data to percentages, we need to calculate the total sum of the data.

To find the percent, divide each individual category by the total sum of data and then multiply by 100.

Press the age ranges below to see sample calculations.

Remember that when we write numbers with thousandths using decimals, we use a decimal point and places to the right of the decimal point. The thousandth place is three places to the right of the decimal point.

For 0-14, there are 2,207,970 people.

2,207,970 ÷ 13,448,495 (total number of people) = 0.164

We round to the nearest hundredth to find our percentage.

Therefore, the percent is 16%.

For 90+, there are 112,609 people. The relative frequency is 0.008, therefore the percent is 1%.

The total number of people is 13,448,495. The relative frequency is 1.0, therefore the percent is 100%.

Test Your Skills!

Practise calculating percent

Complete Table: Ontario Census Profile, 2016 in your notebook or use the following fillable and printable document. Using a calculator or virtual tool, carry out the following steps:

  • Convert the frequencies to the decimal thousandth.
  • Convert the decimal thousandth to the percentage.
Table: Ontario Census Profile, 2016

Age Group

Number (Frequency)

Relative Frequency (as decimal thousandths)

Percentage

0-14

2,207,970

0.164

16%

15-29

2,580,410

30-44

2,579,116

45-59

2,983,190

60-74

2,112,535

75-89

872,665

90+

112,609

0.008

1%

Total

13,448,495

1.0

100%

Press the ‘Activity’ button to access Table: Ontario Census Profile, 2016. 

Consolidation

Reflect and extend

Explore the following completed version of the Ontario Census Profile table from the Action section. Consider how you would describe any relationships in the data now.

  • How can using percentages help people understand the data?
  • What could you do with this data to represent it in another way?
  • Justify your selection.

Ontario Census Profile, 2016

Age Group

Number (Frequency)

Relative Frequency (as decimal thousandths)

Percentage

0-14

2,207,970

0.164

16.42%

15-29

2,580,410

0.191

19%

30-44

2,579,116

0.191

19%

45-59

2,983,190

0.221

22%

60-74

2,112,535

0.157

16%

75-89

872,665

0.064

6%

90+

112,609

0.008

0.8%

Total

13,448,495

1.0

100%

Reflection

As you read the following descriptions, select the one that best describes your current understanding of the learning in this activity. Press the corresponding button once you have made your choice.

I feel…

Now, expand on your ideas by recording your thoughts using a voice recorder, speech-to-text, or writing tool.

When you review your notes on this learning activity later, reflect on whether you would select a different description based on your further review of the material in this learning activity.

Press ‘Discover More’ to extend your skills.

Using a virtual tool, paper, or concrete materials, identify a set of data that includes larger numbers and organize them in a table.

  • Convert the numbers into percentages.
  • List three (3) facts or conclusions that you can draw from your data.
  • List some ways that percentages help us analyze the distribution of data.

Connect with a TVO Mathify tutor

Think of TVO Mathify as your own personalized math coach, here to support your learning at home. Press ‘TVO Mathify’ to connect with an Ontario Certified Teacher math tutor of your choice. You will need a TVO Mathify login to access this resource.

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