Students begin the unit by interacting closely with data. They collect data about themselves by measuring and answering survey questions, studying the different types of responses collected, and identifying the appropriate variables and units being measured.
Students learn about categorical and numerical data. They determine whether a particular survey question will produce one type of data or the other. They also get reacquainted with dot plots (often called line plots in earlier grades) as a way to represent data and make sense of what the data points mean in context (MP2).
- Ask survey questions (orally) and record responses (in writing). Include units of measurement when reporting numerical data (orally and in writing).
- Comprehend and use the terms “numerical” and “categorical” to describe data sets (orally and in writing).
- Interpret various representations of data sets and determine whether it is reasonable that a verbal description represents a given numerical data set.
Let's explore different kinds of data.
For the activity Surveying the Class:
Choose 4–5 survey questions and measurement activities in advance. Be sure to include questions and activities that would produce both categorical and numerical data. The questions about how and how long it takes students travel to school (the first two prompts) and students’ heights in centimeters (the third prompt) will be used in a later lesson, so be sure to include these questions. Provide sticky notes to each student on which they can record their responses. Set up one position in the room for each selected question where students may put their sticky notes to have a visual display of responses.
To collect measurements, prepare measuring stations equipped with the necessary tools (e.g., rulers, measuring tape, etc.), instructions on how to measure, and a way to record the measurements. Students can then rotate through the stations.
- I can collect the correct data to answer a question and use the correct units.
- I can explain the difference between categorical and numerical data.
A set of categorical data has values that are words instead of numbers.
For example, Han asks 5 friends to name their favorite color. Their answers are: blue, blue, green, blue, orange.
A dot plot is a way to represent data on a number line. Each time a value appears in the data set, we put another dot above that number on the number line.
For example, in this dot plot there are three dots above the 9. This means that three different plants had a height of 9 cm.
A set of numerical data has values that are numbers.
For example, Han lists the ages of people in his family: 7, 10, 12, 36, 40, 67.