Fishtank Learning

3rd Grade Math
Unit 2: Multiplication and Division, Part 1
Lesson 19

Objective

Create scaled bar graphs where the scale is provided.

Criteria for Success

Collect and organize categorical data in a table or tally chart. (Spiral from Grade 2)
Represent data in a bar graph in which the axis has an interval of one. (Spiral from Grade 2)
Represent data in a bar graph in which the axis has an interval of more than one, as given.
Include all necessary labels in a drawn bar graph, including a title, category labels, and numerical labels (MP.6).
Answer interpretive questions about data in a bar graph that do not involve the use of operations to solve (e.g., which category is the most popular?) (MP.2).
Understand the purpose of a picture graph as a way to represent a data set to be able to see trends and analyze it more easily (MP.5).

Anchor Tasks - Problem 1

Determine the favorite season of your classmates. Record their answers in the following chart.

Season	Number of Students
Fall
Winter
Spring
Summer

Now, record your classmates’ responses on the bar chart below.

Guiding Questions

How tall will you make each bar to represent the number of students whose favorite season is winter? Spring? Summer? Fall?
How many students were surveyed overall? How can you see that in the bar graph? Does it match what you recorded in your tally chart?
Which season is the most people’s favorite? The least? How can you see that on the bar graph?
What if more than 10 students responded with their favorite season as being any of them in particular? How could we modify the bar graph so that all of the responses could be recorded?

Notes

This Anchor Task reviews students’ work with collecting and organizing data, as well as constructing bar graphs from Grade 2 (2.MD.10).
It is quite likely that any season in particular will get more than ten votes, especially since we know students’ affinity for summer vacation. If you don’t think that will happen and you want to ensure there's an intellectual need for a scaled axis in a bar graph, you could change the question at hand. When the issue arises of the graph not being tall enough to fit a particular piece of data, you could discuss how the graph could be extended upward to fit the maximum. If students don’t suggest changing the scale on the axes, you could either make the suggestion yourself or just move on to Anchor Task #2.

Anchor Tasks - Problem 2

Construct a bar graph below using the data you collected in Anchor Task #1. Be sure to label your title and categories.

Guiding Questions

How is this bar graph similar to the one in Anchor Task #1? How is it different?
For any season that had an odd number of votes, how can you represent that value?
What are the advantages to having each interval on the axis represent more than 1? What are the disadvantages?

Notes

This Anchor Task introduces the key advancement from Grade 2 to Grade 3, where the interval is greater than 1, connecting to the major work of the grade with multiplication.

Problem Set

View Problem Set

Discussion of Problem Set

How did you represent odd values in #2?
How did you determine how many minutes Charlotte spent reading on Friday in #3? On which two days did she read for the same amount of time? How could you tell that in the graph even without knowing exactly what number of minutes?
What made drawing the bar graph in #4 slightly more challenging than previous ones?
How did you translate from the picture graph to the bar graph? What do you notice about their scales? What did that mean for how you drew the bar graph?
How did you determine the scale in #6?
Does the information change when a bar graph is drawn horizontally or vertically with the same scale? Why or why not?
How is a bar graph’s scale more precise than a picture graph’s? For example, in what ways would it be more difficult to represent the data in #5 with a picture graph where the scale is 3?

Target Task - Problem 1

Raquel kept track of the weather for 60 days. The data she collected is shown below.

It was sunny for 40 days.
It was cloudy for 15 days.
It was rainy for 5 days.

Which bar graph correctly shows Raquel’s data?

Target Task - Problem 2

The bar graph below shows the number of different kinds of coins in Chadwick’s collection. Chadwick also has 25 pennies. Complete the bar graph to show the number of pennies in Chadwick’s collection.

Word Problem

Kieron bought 130 plastic utensils for his 10th birthday party. After the party he had 90 utensils left. 10 people used utensils at the party and they each used the same number. How many utensils did each person use?