Statistics: How many are we?
View Sequence overviewData provides evidence to inform our predictions.
Whole class
Students’ representations from the previous lesson
Each student
Sheet of A4 paper
Task
Revise: In the last lesson, we created representations to help us answer the question: How many are in our class? Our representations may have looked different, but they shared the same information.
Discuss some of the different representations that were used and how they made it easy to answer the question How many are in our class?.
Ask: We know how many were in our class the last two days. I wonder if the story of our data will be the same today.
Allow students to make predictions about how many there are in the class today. Encourage them to use the evidence from their data representations to support their predictions.
Use counting methods from previous lessons to answer the question How many are in our class today?.
Ask: What do you notice about the number of students in our class today?
The number of students may be the same/different. Invite students to infer reasons for this and to explain why they are certain that there are that number in class today.
Ask: How many do you think might be in our class tomorrow?
Provide students a sheet of A4 paper and ask them to create a representation of how many they think will be in the class tomorrow.
Students’ use of language when making predictions
By asking questions like “Why do you think that?”, “What is your prediction based on?” or “How sure are you?” students are encouraged to provide evidence using probabilistic language to articulate their predictions as they are likelihoods not certainties.
Some events are more likely than others and we can express these using words like “likely” or “quite possible”. For example, when predicting how many students might be in the class tomorrow, a student might say, “It is likely that there will about 25 students in our class tomorrow because that is how many students there are today.”
Other events are less likely, and the probability of these events can be expressed using words such as “unlikely” or “not likely”, or “improbable”. For example, “It is not likely that there will be 100 students in our class tomorrow because there has never been more than 25 in our class”.
Students should use data as evidence for how likely or unlikely an event is. In each example above, evidence from the data is given to justify the prediction.
Encourage the correct use of language when students are making predictions and make sure they justify their likelihood of their predictions with evidence from data.
By asking questions like “Why do you think that?”, “What is your prediction based on?” or “How sure are you?” students are encouraged to provide evidence using probabilistic language to articulate their predictions as they are likelihoods not certainties.
Some events are more likely than others and we can express these using words like “likely” or “quite possible”. For example, when predicting how many students might be in the class tomorrow, a student might say, “It is likely that there will about 25 students in our class tomorrow because that is how many students there are today.”
Other events are less likely, and the probability of these events can be expressed using words such as “unlikely” or “not likely”, or “improbable”. For example, “It is not likely that there will be 100 students in our class tomorrow because there has never been more than 25 in our class”.
Students should use data as evidence for how likely or unlikely an event is. In each example above, evidence from the data is given to justify the prediction.
Encourage the correct use of language when students are making predictions and make sure they justify their likelihood of their predictions with evidence from data.
Invite some students to share their drawing on their predictions for how many might be in the class tomorrow.
Discuss:
- What did you notice that is similar about the predictions? What is different?
- The data collected on the previous two days provides evidence to inform our predictions about tomorrow. While the exact numbers may differ, the predictions should be similar to the data collected from the previous two days.
- Which representations were you able to see how many easily? Why?
- Allow students to share which ones they found easy to see ‘how many’ and why. Highlight features such as accurate recording, organisation and clear connection between the prediction and the representation.
Ask the students to share their predictions for the following, using evidence from the data to justify their predictions:
- Could there be 100 students in our class tomorrow?
- Could there be no students in our class tomorrow?
- What about if we asked this question on Friday?