Creating to Scale Planet 2D Models

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The students will be able to convert between centimeter and meter measurements, draw the circumference of Earth using a to scale radius and measure, to scale, distance from the sun in meters.

Big Idea

Student astronauts explore science and math that is out of this world!


This is one of my favorite lessons because it gives students real life measurement application and includes my favorite subject - astronomy.  It is HUGE and could last for a week, but we do it in two days. On the second day we present the findings to our "little buddy" class. 

I start my year with place value and large numbers, which are critical components of this lesson.  Astronomy has astronomically large numbers, that are so large the concepts are abstract to students, and even us adults. 

Consider these astronomically enormous astronomical facts:

  • 108 Earths would fit in Jupiter's red spot.  
  • It took a space probe 9 years to get to Pluto.  
  • Earth passes Mars every 26 months.  
  • Jupiter rotates on its axis a full rotation every 9.9 (round that to 10) hours.  
  • Jupiter is more than four times the distance from the Sun than Earth.  
  • Temperatures between planets can range 400°.  


The math opportunities in studying astronomy are...astronomical and the students get hooked!

In this lesson, students cut out a circle from a to scale radius of a planet in meters (converting meters to centimeters in some cases), measure in meters and cut a string to scale of the average distance from the Sun (rounding to the nearest whole number), research the planet statistics - opening discussion about large numbers, and present their findings.  

Building Team Collaboration

30 minutes

Today is going to be different than any other day.  Students notice the difference when they walk into the room and get ready to copy the agenda.  The agenda for the day includes an overall goal - Planets in a Day! 

To build a pattern and as an organizational strategy, I have my students copy the daily agenda I've posted on the board.  While they are doing this, I explain what each item is on the agenda.  Today I weave throughout the agenda how to successfully complete the goal of creating the to scale planets and informational poster in one day.  I can tell they are excited to get started from all the quiet talk and whispers of "I hope I get Jupiter or Earth or ....!" 

As the students finish copying their agendas, I call them to sit on the carpet in a community circle.  Students quickly filter down to the circle, while we each quietly chat with each other.  I believe in allowing some time for social conversation in the classroom because this helps the students to stay focused on academic talk during lessons. We are, after all, social beings and it is natural to want to speak to one another.

In order for today to be successful, our topic for community circle will be how to work in groups.  I start with the question "What needs to happen for a group of people working together to be successful?"  I toss my Koosh ball to a student, they give their answer and then toss it to another students to answer.  I love using the Koosh because it takes me out of the discussion, as students start to take control of who is called on.  My role is to focus on the students, as this really gives me a good idea on what students know and any misconceptions they have - academically and socially.  We then share, round-robin style, one behavior goal we have for ourselves during the group projects.  As the student return to their desks, I ask them to give an appreciation to another student based on their behavior goal.  I model this, "Emma, I noticed how you are going to work on staying on task today." I love to hear the appreciations, and I know the students appreciate receiving them from one another.   It sets a positive classroom environment.

I can feel the students' excitement to get started, but I have one more activity before they find out who is in their group.  There is a wonderful lesson from Reaching all By Creating Tribes: Learning Communities called Roles People Play.  I use the Tribes lessons/strategies at the beginning of the year straight from the book and during the year I put content into the strategies/lessons.  Roles People Play helps build awareness of helpful group roles, the successful completion of group tasks depends on helpful behaviors and students learn collaborative skills.  I put up a picture from the book of cartoon characters. Each character has a role: encourager, joker, organizer, boss, peace keeper, talker, idea person, sitter, helper and put-downer.  I ask the students to discuss at their tables, giving a minute or two between questions:

"What role do you usually play in a group?"

"What other role(s) would you like to play to help your group?"

As this discussion is going on, I am walking around the room listening and passing out index cards.  I ask the students to fold the index card "hot dog" style and to write on one side a role they would like to play (new or old) and on the other side their goal on behavior from community circle.

Planning for Success

25 minutes

The students and I brainstormed how to form groups. The result is their idea - I would have never thought of this.  We do the math - 27 students and nine planets equals 3 students per group.  (Yes, astronomy buffs. We went with the "Classical Solar System" of 9 planets rather than the IAU definition because the math worked better for us.)

I list 1-9 on the white board and start pulling names with sticks.  The first person I pull then is able to invite another person into their group. The criteria is that they must choose someone they had not worked with very much. Then the third member is again pulled by sticks. 

The most incredible things start happening!  Students who I would have thought wouldn't work together started inviting each other.  A couple of students ask if they can pass so they would be the last ones to go into any group or would partner with someone who was not invited to a group!  When given a chance to take charge of their learning, these kids amaze me.  This activity lasts two days and there was only one disagreement that entire time that I had to step into and walk the students through. 

It's a Go to Explore!

180 minutes

Finally the actual project!  But, the time we've taken to build a positive social skill foundation to increase academic achievement and encourage students to take risks always supports greater time from learning because we have far fewer disruptions.

I go over the Planet handout before students meet in their group, because I want them to understand the tasks.  They are to create a to scale model of the planet they are assigned, cut a string to show its scale distance from the sun, and make a poster showing/explaining the basic characteristics of the planet. Bringing their roles and behavior goal cards, they are then sent to meet in their groups - taking a minute or two to discuss what is written on each person's cards. This creates "support" groups, where students can help each other reach their goals.

The next task is to write a plan on the bottom of the handout. This has to be shared with me before they receive any materials.  I am checking to make sure each person has an active role in participating with their group.  The next three hours are spent creating the scale model planets.  The students take the radius of the planet and trace out a circle using either a compass or a pencil and string.  Students have already learned circumference, diameter and radius. 

One of the areas of measurement, I work with students, on is the conversion of meters to centimeters and centimeters to millimeters (5.MD.1).   In both hand outs, Earth is the base of the measurement - Earth's diameter and Earth's distance from the Sun is equal to one meter.

I am able to have wonderful conversations, such as that when Mercury has a diameter of 1.9 it means one centimeter and nine millimeters and Jupiter's radius is 19.5 centimeters or 19 centimeters plus 5 millimeters.  Students are using mathematical tools appropriately to measure the radius and to trace the circumference of the planets onto paper (MP5).  Problem solving skills and attending to precision in the measurement and use of mathematical vocabulary (MP6) are also a critical part of this lesson. 

One group uses the side of the compass that measures in inches and not centimeters, and they discover their error when their planet is much larger than it should be.  They know this because they know Venus is smaller than Earth, but their model of Venus was larger than Earth.  I don't tell them where the error lies. This is their learning, so they must go back to investigate where it went wrong. I'm aware of this and so I keep an eye on them and when I notice they had spent an appropriate amount of time (frustration was showing), I suggest they look at the labels on either side of the compass to see what the units of measurement are. But I don't the students what the error is, I guide them to see it.

The group creating Jupiter really have to problem solve, because the paper I give them is not wide enough.  They had to cut paper to add to both sides.  This doesn't sound too hard, but they were working with only the radius and figured out they needed to double the radius to get the diameter and so they could easily have rationalized (incorrectly) that they should work with the radius because "it fits". Students tend to think we've planned everything to make it "work, because we often do. It is important to allow students opportunities to confront problems, and fix situations, because it makes learning authentic.

The students then move on to cutting the yarn to represent the planets' distances from the Sun.  This, again, is an opportunity to convert between different-sized standard measurement units within a given measurement system.  It is also an exercise in perseverance and effort for the students with the outer planets. 

I truly love this lesson because it integrates all subjects - math, science, reading, writing and presenting.   We are not able to complete it in one day, but it is a rich task and I wouldn't change the lesson. I devote more time during the school day to it than you may be able to, but the tasks can be broken over more than 2 days if you need to.  The time spent on social skills is truly worth it and the work carries over to other lessons. 

Explaining the Reading Informational Text Integration

This lesson deserves the time we devote to it.  Students are able to use their notes from videos, research they had completed on the Internet, trade books and text books.  The best part of the posters was being able to have students use multiple sources for their research and they learned information in one book could be different from another - the text is not always the best and only source. 

The poster creation ties into the Reading Standards for Informational Text Craft and Structure (RI.5.4, 5, 6) because students determine the meaning of general academic and domain specific words - in this case science and math; they compare and contrast information from two or more texts because the research to derive measurements and descriptions of planets is found in more than one book.

The work also ties to the Reading Standards for Informational Text Integration of Knowledge and Ideas (RI.5.7, 8, 9) because students draw on information from multiple print or digital sources, demonstrating the ability to locate and answer to a question quickly or to solve a problem efficiently, explain how an author uses reasons and evidence to support particular points in a text, identifies which reasons and evidence support which points; and integrate information from several texts on the same topic in order to write or speak about the subject knowledgeable. 


30 minutes

The presentation portion of this lesson really covers the Speaking and Listening Standards.  Students have to engage in a range of collaborative discussion from small groups to presenting to second and third graders (SL.5.1).  They had to summarize information presented and use a visual display to enhance the main facts. 

We presented to our younger buddy class of second and third graders.  We first started by spreading out the strings and then placing the planets at the end of the strings.  Each group  read some of their fact or shared what they learned. (SL.5.2 & 3)  You may want to check to make sure your meeting place is free from noise and distractions. We had other classes come outside for recess and it was disruptive to the presentation. 

The little buddies had some basic knowledge of the planets and were able to ask wonderful questions.  I was really proud of my students their knowledge, and presentation skills.

Reflection on the Entire Lesson

This was a BIG lesson and students (and teachers) need to reflect to improve.  I love the way this lesson integrates all subject.  This is the way I like to teach and I believe the best way students learn.  I remember many years in the past when all my teaching was done with integrated thematic instruction, but I have been pushed to break subjects up into instructional minutes in reading, math etc.  I am so grateful for the Common Core Standards because it is bringing back the importance of integrating subjects and putting the fun back in learning. 

When I do this lesson again I am going to make a note to not teach rotation and revolution until this assignment.  It gave a great movement break in the day and was more relevant to the lesson.  Students began to use to correct vocabulary terms and made comments such as:

"Wow Jupiter rotates in less than one half an Earth day!" 

"Venus takes 244 days to revolve around the Sun!"

I teach in a multiage 4th and 5th grade classroom.  Because my 4th graders stay with me for 5th grade I rotate my curriculum through a year A (social studies theme) and year B (science theme).  The last time I taught astronomy, I did not use this lesson. I am grateful I did use it this year.  Teaching math through science has really gotten my students excited about math and they have real life applications.