Build a “Great” Wall
Teresa Leahy, K-5 Educator
Developed with funding from the MathScience Innovation Center
Major
Understanding
The Great Wall of China is an example of extraordinary ancient engineering.
One reason engineers build walls is to keep people/animals in or out. Engineers
use criteria such as length, height and stability when they design projects such
as a wall. Measurement is an important tool for engineers to meet some of
these criteria. Rounding and addition can be used to estimate the length of the
Great Wall of China.
Grade/Subject
Grade 2: Mathematics, Social Studies, and Engineering
Objectives
Use the engineering design process to plan, design, test and improve a
model.
Measure and record height and length using metric units (centimeters).
Estimate the length of a model using rounding and addition (if time allows).
State and National
Correlations
Virginia Standards of Learning: Social Studies (2.1); Mathematics (2.1(a),
2.1(b), 2.6(a), and 2.11(a))
National Mathematics Standards: Apply appropriate techniques, tools, and
formulas to determine measurements; compute fluently and make reasonable
estimates.
Time
Anticipatory Set: The Great Wall of China
Activity: How Does the Wall Measure Up?
Activity: Design a Wall Segment
Activity: How Long is Our Wall?
Practice
Closure: Drawing Conclusions
Assessment
10 min
10-15 min
25-30 min
10 min
Variable
5 min
Variable
Materials
For the class:
 Laptop & LCD Projector
 Webcam (software installed on laptop)
 Build a “Great” Wall PowerPoint Presentation
 Inflatable globe
 Student handout (one for each student)
 Rounding Number Lines (one for each student)
For each group of students (6 groups):
 Bag of KEVA Planks (about 70)
 Bag containing:
 Masking tape
 Scissors
 Tape measure
 Mongolian Warrior
 Card with group name and length of wall segment
 Ruler
 1 KEVA Plank
Instructional
Strategies
1. Anticipatory Set: Building Context: The Great Wall of China
1.1. Begin by discussing the purpose of walls, their construction and
materials that they are made from using the PowerPoint presentation.
(Notes in PowerPoint provide additional information about walls and
facts about the Great Wall). Talk about how engineers need to think
about criteria such as length, height, strength and stability when they
design walls. Provide students with background information on the
Great Wall of China. Discuss how the wall is a series of walls built by
different emperors at different periods in history. Use the inflatable
globe to locate China and show the approximate length of the Great
Wall. Discuss that the purpose of the wall was to keep invaders out of
China.
2. Activity: How Does the Wall Measure Up?
2.1. Present the design challenge to students. Today they will be the
engineers. They will design and build a model of the Great Wall of
China. The class will work in six groups and each group will be
responsible for making a segment of the wall. The students will be
using wooden blocks called KEVA Planks. They will need to work
together to create a wall segment that is free standing and the correct
size. It must be stable and the correct size in order to prevent a
Mongolian invasion.
2.2. Introduce the steps of the Engineering Design Process. Our first step is
to “Understand the Need.” Remind students that engineers design
according to criteria, the rules that will be used to test and evaluate the
design. The wall segment must be twice the height of their Mongolian
Warrior figures to make it difficult for an invading army to climb the
Build a “Great” Wall
http://MathInScience.info
© MathScience Innovation Center, 2011
wall and attack. The wall must also be the correct length. (This will be
written on the blue card.) To determine the height of the Mongolian
Warrior, students will need to use a ruler. Demonstrate using the ruler
and explain that we will be measuring to the nearest centimeter. Pass
out Student handouts and bags of materials to each group. Students
should only take out rulers and the figures. Have students measure the
height of their figure and come to a consensus of the figure’s height (7
centimeters). Help students as needed. Explain that the wall segment
needs to be twice the height of the figure. Guide students with finding
strategies to double the number “7.” Determine that the wall segment
must be at least 14 centimeters tall. Have students record this on their
handouts.
2.3. The wall segments must be built according to a specified length so that
if the segments were put together there would be no gaps for an
invading army to pass through. Explain that each group will have a
different length segment and that this is written on their blue cards.
Ask students to record their group’s length on their handout. Play the
video in the PowerPoint to demonstrate how to use the tape measure to
measure a piece of tape to the correct length, cut it and place it on the
floor. This will give them a guide for how long their wall should be.
Their tape should be exactly the length given on their card. Review
where to find centimeters on their tape measures. Assign students
places in the room and have students measure their masking tape.
3. Activity: Design a Wall Segment
3.1. When all students have measured their tape, show students their
materials and ask them to take five minutes (or less) to brainstorm how
they will use their materials and draw a plan for their wall. Remind
students that each group will build only one wall so they must agree on
one design to build together. Remind students to think about our
discussion of materials from the beginning of the lesson and tell them
that gaps in the wall are allowed as long as they are not large enough
for a Mongolian Warrior to climb through. When each group has had a
few minutes to plan, draw students’ attention back to their handouts.
When they are finished building, they should measure the actual height
of their wall segment to the nearest centimeter. Then draw a picture of
their wall segment and write a sentence telling how they would
improve it if given more time, other materials, etc. Pass out the
materials and allow them to begin to build.
3.2. Allow students 20 minutes to build, measure, draw and write. While
students are finishing these tasks, take a picture of each wall segment
using the webcam to use later during sharing time (see conclusion).
Ask students to think about improvements that could be made to their
wall. Once each group’s picture has been taken, they should clean up
materials and return to their seats and continue to work on their
worksheet.
Build a “Great” Wall
http://MathInScience.info
© MathScience Innovation Center, 2011
4. Activity: How Long is Our Wall? (If time allows)
4.1. If time does not allow, explain this activity to the teacher to complete
at a later time. Have students turn their papers to the back and explain
that their next challenge is to estimate the length of the entire model if
all of the wall segments were put together. Discuss what operation we
would need to use (addition) and what method of estimation
(rounding). Explain that we will be completing this chart together for
each group. (This chart is included in the PowerPoint; you may project
it onto a white board and record or draw your own on a chalkboard or
whiteboard.) Briefly review place value (tens and ones) and record the
number of tens and ones in each number. Review rounding to the
nearest 10 using slides. Pass out the number lines and guide students to
find each number on the number line and round it to the nearest ten.
Record each rounded number on the handout.
4.2. Once the chart is complete, ask students what they notice about all of
the rounded numbers. (They are all 50.) Ask them can they think of a
strategy to quickly add up this group of 50s. Remind them to think
about place value. If needed, guide them to group the numbers to make
hundreds or to think of 50 as 5 groups of 10. They can then skip count
to get their answer (300 cm.).
Practice
1. Exact Length of Wall Model. Challenge students to find the exact length
of their wall through computation or through the use of manipulatives.
2. Design (or Redesign) Process. Challenge students to make another model
of the Great Wall using different materials. Ask them to use what they
learned about the first wall they made.
3. Use Inches. Challenge students to complete the same activity using
inches. Is the number of inches greater or smaller than the number of
centimeters when measuring the same length? Why? About how many
inches long was their original wall segment? Complete the same math
activities using inches in the computations.
Closure
Ask students to share the wall segments they built using pictures taken with the
webcam. Ask them to evaluate their wall segment for stability (Are they free
standing?) and whether they meet the criteria of height and length? Compare
heights of walls. Discuss their designs and how that affected height and
stability. Ask students about strength. How could their walls be made stronger?
What materials would they use? Would they change their designs?
Extension
1. Peter Rabbit Design Challenge. Read the Tale of Peter Rabbit.
Challenge the students to build a wall (four sided structure) to enclose
Mr. McGregor’s garden to keep Peter out. Explain what perimeter is and
ask the students to measure the length of each wall and add to find the
exact perimeter or estimate the sum. Give the students a minimum
height…the wall must be tall enough to prevent the bunny from jumping
Build a “Great” Wall
http://MathInScience.info
© MathScience Innovation Center, 2011
over it. Students may test the height of their wall height using a bouncing
ball.
2. Timeline. Have students research the building of the Great Wall of China
and create a timeline.
3. Estimate the Sum. Challenge the students to find other situations where
estimating the sum would be useful. Have students solve word problems
where they need to estimate the sum to solve.
Assessment
Sample items are provided for use in checking students’ understanding.
Paper Pencil Test: Build a “Great” Wall
Paper Pencil Test Key: Build a “Great” Wall
Product and Rubric: Peter Rabbit Design Challenge
The following table shows how the assessment items are related to specific
objectives:
Objective
PaperPencil
Test
Use the Engineering
Design Process to plan,
design, test and improve a
model.
Student Product and Rubric
Measure and record height
and length using metric
units (centimeters.)
1,2,3,4,5
Student Product and Rubric
Estimate using rounding
and addition.
6,7,8,9,10
Student Product and Rubric
The Great Wall of China is
an example of
extraordinary ancient
engineering. One reason
engineers build walls is to
keep people/animals in or
out. Engineers use criteria
such as length, height and
stability when they design
projects such as a wall.
Measurement is an
important tool for
engineers to meet some of
these criteria. Rounding
Build a “Great” Wall
Product/
Performance
http://MathInScience.info
Student Product and Rubric
© MathScience Innovation Center, 2011
and addition can be used to
estimate the length of the
Great Wall of China.
Teaching Tips
Background Information:




Each group is named for a geographical feature in China or a dynasty.
Information about each is found on the back of the blue cards for
enrichment.
You may choose to assign jobs in the groups. For example, one student to
hold the tape measure, one student to unroll the masking tape, one student
to draw the line at the correct length, and one student to cut the tape.
Download the “Cool Timer” to your laptop and display the countdown as
students plan and later build their wall segments. This will allow them to
manage their time.
If students are having difficulty coming up with a plan, you may prompt
them to discuss different ways to position and stack the Keva planks.
Where do I obtain materials used in this lesson?


KEVA planks were used as building materials. To find out more about
KEVA planks or how to purchase them, visit http://www.kevaplanks.com/.
Mongolian Warrior figures are available from Playmobil at
http://www.playmobil.com/index.html.
Technology Instructions:


References
Use an extra USB cable for the webcam to allow you walk around the
room to take pictures of the students’ structures.
If no webcam is available you may have students take a “tour” around the
room to view the different wall models as students share their designs.
Background Information on the Great Wall of China:
Dutemple, L.A. (2003) The Great Wall of China. Minneapolis: Lerner
Publications Company.
Lynette, R. (2005). The Great Wall of China: Great structures in history.
Detroit: Kidhaven Press.
Engineering is Elementary
The Engineering is Elementary® (EiE) project fosters engineering and
technological literacy among children. EiE is creating a curriculum that
integrates engineering and technology concepts and skills with elementary
science topics with connections to literacy and social studies. Their unit “A
Sticky Situation: Designing Walls” has connections to the Great Wall of China
and building a wall to protect a garden from rabbits.
http://www.mos.org/eie/walls.php
MathScience Innovation Center
Information on educational programs available to students, teachers and school
Build a “Great” Wall
http://MathInScience.info
© MathScience Innovation Center, 2011
divisions and procedures for registering for programs.
http://msinnovation.info
Math In Science: Online Educational Programs
Learn through online virtual classrooms, web-based lessons and online
courses. Access proven lesson plans and instructional modules.
http://mathinscience.info
Build a “Great” Wall
http://MathInScience.info
© MathScience Innovation Center, 2011