2nd Grade Science : Unit #3 - Unit 3 - Apples, Pumpkins and Bread!! OH! My!! : Lesson #7

It's All in the Numbers

Objective: SWBAT make predictions with three different data measurements, gather that data and check their predictions.
Standards: MP5 SP3 SP4 SP5
Subject(s): Science
60 minutes
1 Setting the Stage - 5 minutes

This lesson is a piece of a larger investigation that spans many days and encompasses a large amount of learning and skills with one unifying concept: Apples.  The apples are important for this unit in my district and community.  My hometown is home to some of the largest fruit growing orchards in our state.  Our fruit is exported world wide and because of this, it is required that teachers in my district teach about the importance of the apple to our valley and commerce.  

This lesson focuses on the concept of the apples and their sizes. From the standpoint of the orchard growers in my valley, it is important for selling purposes that apples are grown as closely to a uniform size as can be managed.  Fruit is packed and shipped in boxes that place fruit of like size and weight in the same boxes.  From a scientific point of view, scientists use models (real and replica) to make observations.  This lesson allows the students to practice making mathematical observations.  They are able to practice describing, measuring, and comparing quantitative data (SP5)

My students are divided up into teams of four and five students (Typically, I prefer to have no more than five. However when numbers in classrooms are random, it is necessary to adjust your teams). The teams each receive one apple to use for the duration of this work.

2 Engage - 5 minutes

This lesson uses the same team apples that are used back in the Apple Observation Lesson.

I begin by asking students to get out their Student Research Data.  Reminding them that we are not finished with our work on their team apples.  We have more data to gather and analyze.  The students are very familiar with this vocabulary by now. We have used the words, data and analyze quite a bit by this point in the school year. 

I explain that with today's part of the investigations, we are going to only be working on one page... page 5.  This page focuses completely on making predictions and testing them to check our predictions.  Scientists use prior experience to make predictions.  In planning this lesson, it came strategically placed after the Observation lesson.  It is important the children have had some experiences already observing the apple to be comfortable enough to make predictions about the height and weight of the apple.  It offers an opportunity to make some inferences within their predictions.  

I ask the children to look carefully at their team apple (the apples are in the center of each table team).  I remind them about the investigation we completed earlier in the school year when we learned about measurement tools.  I ask them if they remember what we used for our measurement tool during that lesson....I am hoping they remember "paper clips."  Which they do.  

I explain that this time we will be using a larger measurement tool and I show them the blocks. 

"During this investigation, you are going to make two predictions: one about the height and the second about the weight of your apple."  We have practiced making predictions too.  I ask...."Does anyone remember what a prediction is?" 

I am hoping to hear something like, "it is what we think the answer will be, before we do anything."  This would be the simplest way a seven-year-old would explain a prediction.  

3 Explore - 15 minutes

I show the students slide 5 on the Power Point on the screen and ask them to turn to the same page in their student booklet.  

I explain that I am going to give them just a few minutes to look a the apple and make a prediction about the number of blocks they believe it will weigh.  I demonstrate and model my own thinking on the screen and write my prediction on the screen.  Reminding the students again to think about their first experience with predictions and use that knowledge to make a prediction with the apple (SP3).  

I instruct them to do this and write their predictions on their recording sheet.  

I go through the same modeling with the height as well.  I explain that they will only measure the height of the apple from the table top to the stem of the apple.  I demonstrate what this would look like.  Again, I model writing my own prediction.  I choose a prediction that is relatively close to accurate, but not so accurate that they children can copy my prediction and not have to really rationalize their prediction.  I write '5 blocks' on my documenting form on the screen.  

I instruct the children to make their own predictions and write those down as well.  

Once the children have all documented their predictions, I explain that they may begin weighing and measuring the apples. 

The students work through their work easily and really do not struggle to count out the blocks for height or weight.  They write their final data on the documenting page. 

I am circulating throughout the classroom while the students are working. I am making mental notes about the strategies either being used or not.  Most children do a solid job of counting out and balancing the blocks with the apple and even easily measure their apple in height with the blocks.

Checks for Understanding

I immediately notice two common misconceptions. 

The first being, children erasing their original prediction and writing in the accurate measurement.  I realize quickly they are concerned with being right and not wanting to make a mistake.  Even though we have spoken often about scientists learning from their mistakes and using those mistakes to further their own thinking. I realize that this is a common developmental age issue.  I make note to address this in later lessons.  

The second observation I notice is the confusion about what we are using as a standard of measurement.  Even though the children know that they are weighing in blocks, they struggle to use the language to explain the measurement.  Again, I make note to address this later in more lessons. 

4 Evaluate - 10 minutes

After the children have all had a chance to document their data, we look at our results.  I ask the children to look a their results. 

"What do you notice about your prediction and the actual measurement?" Some children will make the connection that they are close to their predictions.  While others, may not understand the differences.  Some, even still will be erasing answers thinking that their prediction must match the accurate measurement.  

"What happens if your prediction is not close to your data?" 

I am listening for: "It is ok, if they do not match." 

"Do the two measurements need to be the same?" 

I am listening for:  "No, they do not need to be the same."

"If a scientist is off in their measurements, what can they do with this information?" 

I am listening for: "They can learn from that difference."

After the conversation, the children are able to 

My Students Knowledge
Developing a Conceptual Understanding

After having the dialogue with my students about the predictions and their results, I was sure that many of them did not understand that the prediction and the result did not have to be the same.  I realized that this misconception would be one I would need to address again if not many times.