Minds On
What does the data tell us? Part 1
A Grade 2 class counted the number of books they read each month from September to the end of January.
They displayed their data in a pictograph.
| Month | Number of Books Read Each Month |
|---|---|
|
September |
|
|
October |
|
|
November |
|
|
December |
|
|
January |
|
“Key: One
represents 5 books.”
If possible, examine the table with a partner. What do you notice?
Record your thinking using a method of your choice. You can type, write, use speech to text, or create an audio recording.
Press ‘Answer’ to check your understanding.
Number of books read each month. The key shows that a picture of one book represents five books.
September has five books. October has four books. November has five books. December has five books. January has seven books.
We can skip count by 5 for each picture of a book to count how many books were read each month.
In September, we can skip count by 5s 5 times so, 25 books were read
In October, we can skip count by 5s 4 times so, 20 books were read.
In November, we can skip count by 5s 5 times so, 25 books were read.
In December, we can skip count by 5s 5 times so, 25 books were read.
In January, we can skip count by 5s 7 times so, 35 books were read.
Action
Exploring data on a pictograph
A pictograph is a graph that displays data using pictures or symbols. In a pictograph, each symbol represents a number.
A key on a pictograph shows the number represented by each symbol. For example, 1 book symbol, represents 5 books.
Let’s examine the data again. This time, tallies and totals have been added to the table.
|
Month |
Number of Books Read Each Month |
Tallies |
Totals |
|---|---|---|---|
|
September |
|
25 |
|
|
October |
|
20 |
|
|
November |
|
25 |
|
|
December |
|
25 |
|
|
January |
|
35 |
Key: One represents 5 books.
There is a pictograph. The first column is titled, Month. The second column is titled, Number of books read each month. The third column is titled, Tallies. The fourth column is titled, Totals.
The key shows that a picture of one book represent 5 books.
September has five books and there are 25 tally marks. October has four books and there are 20 tally marks. November has five books and there are 25 tally marks. December has five books and there are 25 tally marks. January has seven books and there are 35 tally marks.
What does the data tell us? Part 2
The pictograph shows how many books a Grade 2 class read from September to the end of January.
What is the mode in the set of data in Part 1?
HINT: The mode is the category or number that occurs most often in a set of data. For example, the mode of 0, 3, 6, 7, 11, 7 is 7.
Press ‘Answer’ to check your understanding.
The data set for our pictograph is: 25, 20, 25, 25, 35. Since the number 25 appears most often, the mode for this data is 25.
May temperatures
Let’s try to find the mode of a different set of data!
Students in a Grade 2 class measured and recorded the highest temperature every day for two weeks in the month of May in a chart.
| Daily Highest Temperature in Degrees Celsius | ||||||
|---|---|---|---|---|---|---|
|
May 1 
14 degrees Celsius |
May 2
14 degrees Celsius |
May 3 
16 degrees Celsius |
May 4 
18 degrees Celsius |
May 5 
17 degrees Celsius |
May 6
14 degrees Celsius |
May 7
16 degrees Celsius |
|
May 8 
20 degrees Celsius |
May 9
16 degrees Celsius |
May 10
14 degrees Celsius |
May 11
16 degrees Celsius |
May 12 
13 degrees Celsius |
May 13
20 degrees Celsius |
May 14
20 degrees Celsius |
The class displayed their data in a line plot.
A line plot titled "Highest Daily Temperature for 2 Weeks in May." The number line is labelled "Temperature (degrees Celcius)," it starts at 13 and goes up by ones to 20. 13 has 1 X, 14 has 4 X's, 15 has no X's, 16 has 4 X's, 17 has 1 X, 18 has 1 X, 19 has no X's, 20 has 3 X's.
Find the mode in this set of data.
What do you notice? Which temperature appears most often?
You probably noticed that 14 degrees Celsius appears four times and 16 degrees Celsius also appears four times. This means this set of data has two modes.
A set of data can have more than 1 mode when two or more categories have the same frequencies that are greater than any others.
14 degrees Celsius and 16 degrees Celsius both appear four times. This is more than the other temperatures recorded.
Consider:
- What does the mode tell you about the temperatures in first 14 days of May?
Record your thoughts using a method of your choice.
Consolidation
Teaching about mode
Use the following tally table to find the mode or modes.
The tally table below shows the number of hours a Grade 2 student slept each night for two weeks.
| Number of hours slept each night | Tally marks |
|---|---|
| 6 | |
| 7 | |
| 8 | |
| 9 | |
| 10 |
The tally table explains the number of hours a grade 2 student slept each night for two weeks. The first column shares the options of the survey. The options are: 6 hours, 7 hours, 8 hours, 9 hours, 10 hours. The second column has the tally marks for each option. 6 hours has zero tally marks. 7 hours has 3 tally marks. 8 hours has 5 tally marks. 9 hours has 3 tally marks. 10 hours has 3 tally marks.
Use the data in the tally table to create a graph of your choice. You can create a line plot, pictograph, or bar graph or create a detailed written or audio description of how you would create your graph.
Press ‘Review’ to recall what line plots, pictographs and bar graphs need:
A line plot needs:
- A title
- A data source
- A number line that is labelled and has values in different categories
- X’s to mark the number of each value
A pictograph needs:
- A title
- A data source
- A picture to represent the data. Consider, what picture will work best?
- The categories listed in rows
- A key (to show how many each symbol or picture represents)
A bar graph needs:
- A title
- A data source
- Categories for each bar
- Labels for the x-axis along the bottom and the y-axis along the side
What would you share about how to find mode on a graph? Record your instructions using a method of your choice.
Reflection
Use the following questions to reflect on your learning. You can record your thinking using a method of your choice.
- Do you prefer to find the mode in a tally table, a pictograph, or a line plot? Why?
- What does the mode tell us about a set of data? How might the mode help us understand the set of data?
How do you feel about what you have learned in this activity? Which of the next four sentences best matches how you are feeling about your learning? Press the button that is beside this sentence.
I feel…
Now, record your ideas about your feelings using a voice recorder, speech-to-text, or writing tool.