Group Size: Small Groups


Summary: An activity creating boxes for candy helps students understand measuring volume and surface area.
Main Curriculum Tie: Mathematics Grade 6 Strand: GEOMETRY (6.G) Standard 6.G.4 Represent threedimensional figures using nets made up of rectangles and triangles, and use the nets to find the surface area of these figures. Apply these techniques in the context of solving realworld and mathematical problems. Materials:
Additional Resources
Books
Navigating through Measurement in Grades 35, by NCTM; ISBN 0873535448
Math on Call, A Mathematics Handbook, by Great Source Education Group; ISBN 0669457701
Attachments
Background For Teachers: In this activity, students will be working with nets to determine
the surface area of various boxes. A net is a twodimensional pattern
that can be folded to make a threedimensional model of a solid, and is
an excellent visualization for surface area. Surface area represents the
number of squares that cover the surface of a prism. The formula for
surface area of a rectangular prism is: SA = 2(l x w) + 2(l x h) + 2(w x h).
Students should already know how to find the area of two
dimensional figures and the volume of threedimensional figures.
Intended Learning Outcomes:
4. Communicate mathematical ideas and arguments coherently to peers,
teachers, and others using the precise language and notation of mathematics.
5. Connect mathematical ideas within mathematics, to other disciplines, and to
everyday experiences.
Instructional Procedures: Invitation to Learn
Give groups of students copies of Net 1 and Net 2. Show them
how to make the nets into boxes. Ask your students how the
boxes are alike (volume is the same). Ask them how the boxes are
different (different shapes). Ask them what the dimensions are for
each box. Have them cut the tape and unfold the boxes. Have the
students find the surface area for each net. Point out that although
the boxes had the same volume, the surface area is not the same.
Instructional Procedures
 Put students into pairs (or groups).
 Tell students that the box company where they work just got a
new contract from The Candies R Us Candy Company. Their
new assignment is to design boxes with lids that will hold 12 of
their chocolate candies.
 Hold up a multilink cube and tell them that the chocolate
candies have the same dimensions as the cube.
 Explain to your class that the volume of the boxes are fixed at
twelve, since that is how many chocolate candies the company
wants in each box.
 Tell students that their job is to review all of the possible
rectangular boxes with a volume of twelve, and then prepare a
presentation to the owners of Candies R Us. Their presentation
needs to include a model of the box, and the reasons for
choosing that box.
 Ask students what they think the owners of the candy company
would want in a box. Brainstorm ideas. (They might want
a box that is easy to ship, convenient to stack and store, and
profitable). Ask them: What would make a box profitable?
(You might want to remind them about the Invitation to Learn,
but do not tell them about the connection between surface area
and the amount of material needed to make the box. Hopefully,
if they don't think about it yet, they will discover it as they do
the activity.)
 Give each pair of students twelve multilink cubes and several
sheets of twocm graph paper.
 Hand out the worksheet Candies R Us Box Designs
.
 Have students discover all of the possible boxes that would hold
twelve chocolate candies (there are four possible choices).
 Have them create a net for each of the boxes. Remind them that
the paper should not overlap.
 Have the students fill in the chart on the Candies R Us Box
Designs worksheet. You may need to demonstrate the data for
one box so they understand how to organize the information.
 Ask students if they notice any patterns in the data on their
charts (same volume, V = l x w x h, dimensions are all factors of
twelve).
 Have pairs decide which box they think is best, and discuss the
reasons behind that choice.
 Have the pairs make their presentation to the class. They need
to show a model of the box that they would recommend and
talk about the reasons that box would be the best option for the
candy company.
 Discuss the results of the activity. What do we call the
measure of the number of multilink cubes that a box will
hold? (Volume) What was the volume of the boxes you made
for Candies R Us? (Twelve) Did the volume change from
box to box? (No) What units do we use to measure volume?
(Cubic units) Why? (Because volume is a threedimensional
measurement.) Was there a box that more pairs recommended?
Why? (This should lead to a discussion on surface area.)
 Explain to your students that the net they made for each box
represents the surface area of the box, or the amount of material
needed to cover the box. Ask them if they noticed a general
rule for finding the surface area of any box (It is the sum of
the areas of each face of the box.) What units do we use to
measure surface area? (Square units) Why? (Because area is a
twodimensional measurement.) The volume stayed the same
for each box, but what happened to the surface area? When
might you want to find the surface area of something?
 Come up with a formula for finding surface area of a right
rectangular prism.
SA = 2(l x w) + 2(l x h) + 2(w x h).
 Have students draw a net in their journal and explain what
it represents (the surface area of a rectangular prism). Have
them write a summary of their findings from the activity. Have
them explain how to find the surface area of a right rectangular
prism.
 Have students complete the assessment MixedUp Pieces.
Extensions: Curriculum Extensions/Adaptations/
Integration
 Find the area of other right prisms by using the area of
triangles, rectangles and parallelograms.
 Create advertisements for boxes. Use poster board to cover the
surface area and decorate the box.
 Create boxes to hold 18 chocolate candies.
 Write a letter to owners of Candies R Us outlining their
recommendations and enclosing the net from their box of
choice. Have the students discuss the box’s surface area
and volume and the reasons behind choosing that box. Tell
students to make their letter convincing, so the owners will
choose their box.
Family Connections
 With a family member, find the surface area of a cereal box or
other box from home.
 Wrap a present from home without any overlap. Measure how
much wrapping paper was needed to cover the surface area of
the box.
Assessment Plan:
 Informal assessment includes observation and class discussions
 Candies R Us Box Designs
 Presentation – model of box, reasons behind choice, discuss
volume and surface area
 MixedUp Pieces
Bibliography: Research Basis
Reid, J. (1992). The effects of Cooperative Learning with Intergroup Competition on the Math
Achievement of Seventh Grade Students. ERIC Source (ERIC # ED355106). Retrieved
November 28, 2007, from www.eric.ed.gov.
This paper reports a study designed to determine the effect of
cooperative learning strategies on mathematics achievement in
seventh graders. Students were divided into two groups. One group
participated in cooperative learning strategies, and the other group
received individual/competitive instruction. Pretests indicated no
differences existed in the groups prior to instruction, but that the
cooperative learning groups performed significantly higher on the post
test. The paper concluded that cooperative learning strategies are more
effective in promoting mathematics achievement.
Reineke, J.W. (1993). Making Connections: Talking and Learning in a FourthGrade Class.
Elementary Subjects Center, Series No. 89. Eric Source (ERIC # ED365537). Retrieved
December 10, 2007, from eric.ed.gov.
This report describes a fourth grade classroom where students’
thinking was made public through discussions in which students
presented and justified their interpretations of, and solutions to, the
problems presented in class. Results suggested that the teacher and
her students learned to talk about mathematics in ways that made their
thinking visible and indicated that they know mathematics in fresh,
inventive ways.
Author: Utah LessonPlans
Created Date : Jul 14 2008 14:10 PM
