MPACT

Hanging MobileMPACT TERC 2020

IntroductionThis hanging mobile activity is designed for families with children in grades 4-7. It includesactivities for making and math.This picture shows the one kind of mobilethat you can make. It also show the parts ofthe mobile. You can make many differentmobile designs. You’ll make it for a friend, afamily member, or a community center.Just follow the steps in this activity, thatlead you through design and making—andlearning math along the way.For Grown UpsFor ChildrenThis activity is for you and your kids to dotogether or for your kids to do on their own.You don’t have to know the math inadvance. Be open to exploration, and askquestions such as “How did you do that?”and “How do you know?”Gather the following materials and getready to make a set of shapes. Along theway you’ll learn a bit of math. If you getstuck on any step, take a breath and tryagain. It’s okay if you need to restart anduse more materials. Good luck and havefun! TERC 20202

Gather MaterialsTools ScissorsTapeGluePencils or pensSmall object found in your house tohang on mobileOptional: paint, markers, glitter,ribbon, or something to decorate theobjects.Paper for 3D objects Stiff paper or thin cardboard. It canbe: Cereal boxes File folders Cardstock Plain paper. It can be: printer paper decorative paper Graph paper You can print the graph paperon the next pages or use a ruler to make your own. TERC 2020For arms – A straight stick about 10-15inches long. It can be: A twig from a tree, orA skewer, orAn old paintbrush, orAnything you can findString for attaching parts. It can be: String Twine Yarn Anything stringy you can find3

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Plan and DesignCollect Ideas Choose a friend, family member, orcommunity organization to make amobile for. Find out what they like: colors,shapes, animals, or other ideas youhave. Make notes about what they like, soyou can remember this later.Hanging Mobile Requirements The mobile must have at least onearm. The mobile must have at least threeobjects hanging from the arm/s. Two objects must be geometricshapes made with nets. The other objects can be anythingabout the same size as the shapes(The heavier helps). The mobile with all the objectshanging must balance.Sketch out a design On paper, draw the mobile: arms, string, and objects. Draw two different ideas. Check if they meet the requirements. Choose the idea you want to use.Fold Net into a CubeA cube is a 3-dimensional shape with sixsquare faces. Look for a cube around thehouse.A net is a flat shape you can fold to make a3D shape. TERC 2020On paper, draw the net of a cube yousee here. It can be any size that fits onyour paper.Cut out the net.Fold the net to make a cube shape.This is your pattern for making a cubefor your mobile.Talk about it: How did you know howto fold the net?6

Different ways of making a net for a cubeMake a net bytracing a smallsquareMake a net by tapingtogether smallsquaresDo this if youhave tapeMake a net withgraph paperDo this if you havegraph paperMake a net by tracing a small squareYou’ll need a sheet of letter sized paper (8.5 x 11 inches), scissors, and a pencil or pen.Step 1: Fold in half TERC 2020Step 2: Unfold7

Make a net by tracing a small square (cont.)Step 3: Fold to centerStep 4: Fold to centerStep 5: UnfoldStep 6: Cut out one stripStep 7: Fold diagonal line to make asquare.Step 8: Fold downStep 9: UnfoldStep 10: Cut out square TERC 20208

Make a net by tracing a small square (cont.)Step 11: Use the square to traceStep 12: Trace the square to make a “t”shapeStep 13: Cut out shapeStep 14: Finished netMake a net with squaresStep 1: Fold in halfStep 2: UnfoldStep 3: Fold to centerStep 4: Fold to center TERC 20209

Make a net with squares (cont.)Step 5: Cut out two stripsStep 6: Fold diagonal lineStep 7: Fold downStep 8: UnfoldStep 9: Cut out squareStep 10: Make 6 squaresStep 11: Use the squares to make a“t” shapeStep 12: Tape the squares together TERC 202010

Make a net with graph paperStep 1: Decide on how many unitsYou know that the net must have 4squares in a row. Count the totalnumber of units of the longest side.What’s the length of the side of thebiggest square you can make?Step 2: Count the units and draw asquareStep 3: Make a “t” shape withsquaresStep 4: Cut out around the shapeStep 5: Finished net TERC 202011

Make a net of another shape Choose another 3D shape to makewith a net. (See the shapes in theimage to the left.)Draw the net on paper. Imaginefolding it up. Change the net untilyou think it will work.Cut out the net.Test it: Fold it to make your shape.If it works, you will use this net tomake more nets. If it doesn’t work,fix your net.Here is an example net.Talk about it: What 3D shape can beformed from this net? TERC 202012

Make the 3D shapesUse the nets you just made.1.2.3.4.5.6.7.8.Put the nets flat on thin cardboard or thick paper.Trace around the nets with a pencil to draw the nets on the thin cardboard. Or youcan glue your paper net on the thin cardboard.Cut out the cardboard nets.Decorate the cardboard nets with pens or markers.Fold up the cardboard nets into 3D shapes.Attach a string for the shape to hang from.Tape the edges of your net together to make the 3D shape.Add more decorations, as you like.Put together the mobileYou need the arm, the string, and the objects for your mobile. The objects are the 3Dshapes you made and one you found around the house.1.2.3.Hang the two 3D shapes you made at either end of the arm.Balance the arm on your finger. Tie a string to this place on the arm. The stringshould hang above and below the arm.Hang an object from the middle string.Give the mobile to the user1.2.3.Bring the mobile to the person or group you made it for.Hang the mobile for them. Let them watch it moving.Ask if it fits with the ideas they gave you when collecting ideas. TERC 202013

Try spatial reasoning with netsGiven a net, which cube is NOT possible?If you are not sure, make the nets below and decorate them the same way. Fold the netsinto cubes. Rotate your cubes to help you find the cubes that are possible and the cubesthat are not possible.These spatial reasoning challenges come from 123test.com. For more spatial reasoningchallenges, check it out at: https://www.123test.com/spatial-reasoning-test/. TERC 202014

Learn about surface areaYou have made two 3D shapes from nets.Talk about it: Describe how the net is related to its 3D shape. Try to explain it to ayounger child.The surface area of a 3D shape is the sum of the areas of the faces of the shape. Thesefaces make up the net of the 3D shape.Calculate the surface area of this rectangular prism. Sketch a net to help you.The surface areaof a 3D shape isthe sum of thearea of theshapes in the net.You can get it byfiguring out thearea of each face.Some of the facesmay be the sameshape. TERC 202015

Additional ResourcesPlay this game to learn more about nets of cubes. There are fun animations when youcheck youranswers. ions/Interactives/Cube-Nets/Take this quiz to boost your spatial reasoning est/What shape would this net make? TERC 202016

Answer KeyMake a net of another shape, page 12It is a pyramid with a square at the bottom. So, a square pyramidTry spatial reasoning with nets, page 14Top cube answer: DBottom cube answer: BLearn about surface area, page 1528 square units TERC 2020Additional Resources, page 16It’s a triangular prism17

About MPACTMPACT is made possible byan Education Innovationand Research grant by theU.S. Department ofEducation to develop andimplement a programbringing the exciting andever-more-broadly-usedtechnologies of 3D modelingand printing to middleschoolers in 50 classrooms.90% of MPACT’s fundingcomes from the EIR. 10%comes from our generousdonors—including the gift ofyour time. TERC 2020About this activityInstructional Designers:Hee-Joon Kim, Jennifer Knudsen, Teresa Lara-Meloy,Ken RafananGraphic Design & Illustration:Ada Ren-MitchellMultimedia online version available at:https://mpact3d.terc.edu/hanging-mobile/18

Make the 3D shapes 13 Use the nets you just made. 1. Put the nets flat on thin cardboard or thick paper. 2. Trace around the nets with a pencil to draw the nets on the thin cardboard. Or you can glue your paper net on the thin cardboard. 3. Cut out the cardboard nets. 4. Decorate the