Grade 2
Science
Unit: 02
Lesson: 03
Suggested Duration: 8 days
Un reto de construcción
Lesson Synopsis:
Students have had the opportunity to explore, sort, and classify materials by their physical properties. In addition, they
have experimented with changes caused by heating and cooling. In this lesson students will use these skills, along with
creativity and careful thinking, to complete an engineering design challenge: designing and building a bridge.
TEKS:
2.5
2.5D
Matter and Energy. The student knows that matter has physical properties and those properties determine how it is
described, classified, changed and used. The student is expected to:
Combine materials that when put together can do things that they cannot do by themselves such as building a tower
or a bridge and justify the selection of those materials based on their physical properties.
Scientific Process TEKS:
2.1
2.1A
2.2
Scientific investigation and reasoning. The student conducts classroom and outdoor investigations following home
and school safety procedures. The student is expected to:
Identify and demonstrate safe practices as described in the Texas Safety Standards during classroom and outdoor
investigations, including wearing safety goggles, washing hands, and using materials appropriately.
Scientific investigation and reasoning. The student develops abilities necessary to do scientific inquiry in
classroom and outdoor investigations. The student is expected to:
2.2A
2.2B
Ask questions about organisms, objects, and events during observations and investigations.
Plan and conduct descriptive investigations such as how organisms grow.
2.2D
Record and organize data using pictures, numbers, and words.
2.3
Scientific investigation and reasoning. The student knows that information and critical thinking, scientific problem
solving, and the contributions of scientists are used in making decisions. The student is expected to:
2.3A
Identify and explain a problem in his or her own words and propose a task and solution for the problem such as lack
of water in a habitat.
2.4
Scientific investigation and reasoning. The student uses age-appropriate tools and models to investigate the natural
world. The student is expected to:
2.4A
Collect, record, and compare information using tools, including computers, hand lenses, rulers, primary balances,
plastic beakers, magnets, collecting nets, notebooks, and safety goggles; timing devices, including clocks and
stopwatches; weather instruments such as thermometers, wind vanes, and rain gauges; and materials to support
observations of habitats of organisms such as terrariums and aquariums.
2.4B
Measure and compare organisms and objects using non-standard units that approximate metric units.
GETTING READY FOR INSTRUCTION
Performance Indicator(s):

In small groups, design and build a bridge that can span a distance of 15 inches (38cm) be about 6 inches (15
cm) off the ground, and support a load (determined by the teacher). Justify the selection of materials based on
their physical properties. Communicate the results of the investigation by recording in science notebooks using
pictures and words. (2.2B; 2.3A; 2.5D)
1E; 3E; 5B
Key Understandings and Guiding Questions:


Los objetos pueden describirse según sus propiedades físicas.
— ¿Qué propiedades físicas sería importante que conocieras para construir un puente?
Se pueden hacer cosas con los materiales para cambiar sus propiedades físicas, pero no todos los materiales
responden de la misma manera a lo que se les hace.
— ¿Cómo responde el papel de forma diferente a la madera respecto a la propiedad de “flexibilidad”?
Vocabulary of Instruction:

propiedades físicas
©2012, TESCCC

puente
06/05/13

extensión
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Grade 2
Science
Unit: 08 Lesson: 01
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suspensión
viga
arco
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columna
plataforma
celosía
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contrafuerte
pesas
carg
Materials:
Refer to Notes for Teacher section for materials.
Attachments:

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Teacher Resource: PowerPoint: Bridges
Handout: Exploring Physical Properties (1 per student)
Teacher Resource: Exploring Physical Properties-Sample Student Responses KEY
Handout: Testing Bridges (1 per student)
Handout: Imagine (1 per student)
Handout: Our Plan (1 per group)
Teacher Resource: Rules and Requirements for Bridge Design Challenge PI
Optional Handout: Cost Sheet PI (1 per student)
Handout: A Final Report PI (1 per student)
Teacher Resource: Instructions for Performance Indicator
Resources and References:

Suggested Books:
 Guarnaccia, S. (2010). The three little pigs: An architectural tale. NY: Abrams Books for Young Readers.
 Lowell, S. (1996). Los tres pequeños jabalíes/The three little javelinas. Blue Ridge Summit, PA: Luna Rising;
Bilingual edition.
 Marshall, J. (2000). The three little pigs. NY: Grosset & Dunlap.
 Trivizas, E. (1997). The three little wolves and the big bad pig. NY: McElderry.
Advance Preparation:
1. Prior to Day 1, locate a book about choosing the right building materials. Several examples, such as The Three
Little Pigs may be available in your media center.
2. Prior to Day 2, gather a selection of materials in a plastic bag for students to explore and observe. These items
may include a toothpick, craft stick, non-flexible straw or coffee stirrer, string, paper clip, 3”x3” pieces of index
card, etc. It’s important to select items with different physical properties that the students learned about earlier,
such as shape, texture, flexibility, and whether the material is a solid or a liquid. Prepare one plastic bag (for easy
distribution) per 3–4 students. Each student will also need a sheet of drawing paper ready.
3. For the Explore – Testing Bridges, each group will need six books of similar thickness (1 ½” each) to act as
abutments- three per side. Gather rulers, as each group will need one for the activity. Collect 40–50 washers,
nuts, bolts, or pennies for the groups to use as weights. You will need small, bathroom cups to put the items in (1
cup per group) The weights will be distributed to the groups as they test the two bridge designs.
4. Prior to Day 5, gather materials for the groups of students to use in building their bridges, including toothpicks,
craft sticks, non-flexible straws or coffee stirrers, string, paper clips, index cards, drawing paper, and tape. The
amount needed of each material will depend on student designs.
5. Prepare attachment(s) as necessary.
Background Information:
This lesson bundles student expectations that address using simple equipment to classify matter and compare changes in
matter and how the physical properties of an object can influence an object’s use.
Prior to this lesson, students have observed, classified, and recorded the properties of objects including relative size,
relative mass, shape, color, and texture. During this lesson, students expand their understanding of the properties of
objects such as shape, mass, temperature, and flexibility and use these properties to combine the objects to do
something that they could not do before. Students will use their previous knowledge of properties of matter, along with
creativity and careful thinking, to complete an engineering design challenge: designing and building a bridge.
GETTING READY FOR INSTRUCTION SUPPLEMENTAL PLANNING DOCUMENT
© 2012, TESCCC
06/05/13
page 2 of 7
Grade 2
Science
Unit: 02 Lesson: 03
Instructors are encouraged to supplement and substitute resources, materials, and activities to differentiate instruction to address the needs of learners.
The Exemplar Lessons are one approach to teaching and reaching the Performance Indicators and Specificity in the Instructional Focus
Document for this unit. Instructors are encouraged to create original lessons using the Content Creator in the Tools Tab located at the top of the page.
All originally authored lessons can be saved in the “My CSCOPE” Tab within the “My Content” area.
INSTRUCTIONAL PROCEDURES
Instructional Procedures
Notes for Teacher
ENGAGE – A Look at Bridges
NOTE: 1 Day = 50 minutes
Suggested Day 1
1. Read a book about a situation where choosing the right materials would
make a difference.
2. After the book has been read,
Ask/Say:
 What were the different building materials used in the book?
Student answers will vary depending on the book.
 What were some of the physical properties of these materials?
Student answers will vary depending on the book.
 What were some of the problems the characters faced when
building? Student answers will vary depending on the book.
 Were all the materials equally good for building a house? Student
answers will vary depending on the book.
 What physical properties would be important to know about for
constructing a bridge? Answers will vary depending on students’
background knowledge.
 During the next few days, you are all going to become engineers,
architects, and builders. You will work in teams to plan, design,
and build a bridge. Before we start, let’s look at some different
bridges around the world.
Materials:
 book (about choosing right building
materials, 1 per class)
Attachments:
 Teacher Resource: PowerPoint:
Bridges
Science Notebooks:
Have students draw a picture of a bridge
that they find useful.
3. Show the Teacher Resource: PowerPoint: Bridges.
4. Ask/Say:
 How might life be different if we didn’t have bridges? Food and
people would have a difficult time getting across our large rivers such
as the Mississippi. We would rely on boats more often. Some families
may not be able to visit each other as often because they live across a
river (Texas/Mexico).
 Who might be affected the most if bridges didn’t exist? Answers
will vary but might include food suppliers, families, and animals.
 In your science notebook, draw a picture of a bridge that you
would find useful. Make sure you are included in the drawing.
Write a sentence or two explaining why the bridge is useful.
EXPLORE – Exploring Physical Properties
Suggested Days 2 and 3
1. Distribute one plastic bag per group of 3–4 students.
2. Introduce the activity:
 Every group will be receiving a plastic bag with some materials.
 You will need to evaluate each of the materials in the bag.
 We will complete the data recording sheet together after you have
had time to explore each of the materials in the bag.
 You will need to recall the physical properties we learned about
earlier: shape, texture, flexibility, and whether the material is a
solid or liquid.
©2012, TESCCC
06/05/13
Materials:
 objects (variety, to explore, see
Advance Preparation, per group)
 resealable plastic bags (to put
objects in, see Advance Preparation,
1 per group)
 chart paper (per class)
 glue (sticks or white liquid, per
group)
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Grade 2
Science
Unit: 02 Lesson: 03
Instructional Procedures
Notes for Teacher
3. Allow time for students to explore each material in the plastic bag.
4. Distribute the Handout: Exploring Physical Properties.
Attachments:
 Handout: Exploring Physical
Properties (1 per student)
5. Complete the chart as a whole group. It is important to allow discussion
time as each material is discussed, particularly the columns “What happens
when I…” and “Could be useful for…” The students need to transfer the
knowledge they have about physical properties and think how these
Check for Understanding
properties would be useful when designing a bridge.
Instructional Notes:
As you discuss each of the materials,
tape a piece of the material to the chart.
This gives all students the opportunity to
see the material and read the name of
the material. This will assist in the
Explore activity.
Material
Physical
Properties
What
happens
when …
Could be
useful
for…
Straw
Craft
stick
Card
stock
Science Notebooks:
Complete the handout and glue into
notebook.
EXPLORE – Testing Bridges
Suggested Day 3 (continued)
1. Students will make an arch bridge and a beam bridge in order to test how
much weight these two designs can support. In addition, they will observe
how each bridge is affected by the weights.
2. Hold up four 5”x7” index cards, and have the 2 stacks of books in front of
you.
Say:
 You will be using four index cards and these stacks of books to
create and test an arch bridge and a beam bridge. The directions
for constructing the bridges are on the Handout: Testing Bridges
recording sheet.
3. Distribute the recording sheet Handout: Testing Bridges. Read the
directions to the students. Distribute the materials to each group of 3
students: 8 index cards, 6 books, and a ruler.
4. Provide the following instructions:
 Stack the books three high, and place them 5 inches apart.
 The books are going to act as the abutments for your bridges.
 You may use the ruler to measure 5 inches, or you can place the
index card across the books to see that 1 inch is resting on each
stack of books. Allow a few minutes for students to stack the books
the correct distance apart.
©2012, TESCCC
06/05/13
Materials:
 index cards (5” x 7”, 8 per group)
 weights (such as washers or
pennies, per group)
 cups (bathroom, small, to hold
weights, 1 per group)
 books (of similar thickness (@1 ½”
each, see Advance Preparation, 6
per group)
 rulers (1 per group)
 glue (sticks or white liquid, per
group)
Attachments:
 Handout: Testing Bridges (1 per
student)
Instructional Notes:
Students will practice measuring skills as
they place the two stacks of books 5
inches apart. Students should be able to
page 4 of 7
Grade 2
Science
Unit: 02 Lesson: 03
Instructional Procedures
Notes for Teacher
5. Ask:
 Which bridge do you think will be the strongest and why? Allow a
few minutes for students to write their prediction in their science
notebook.
accomplish this task in less than five
minutes. Encourage students to work
with each other.
Vocabulary note: You may need to
explain the term “abutment”.
6. Direct students to build their first bridge. As they are doing this, distribute a
cup with weights in it to each group.
7. Provide the following instructions:
 You will be testing your bridge with the cup of weights.
 Place the empty cup in the center of the bridge, and carefully add
weights to the cup.
 Count how many weights your bridge can hold.
 Do not drop the weights in the cup because this could cause your
bridge to collapse earlier.
Science Notebooks:
Students should record their prediction in
their science notebook.
Students should complete the Handout:
Testing Bridges as they complete the
activity. Glue into science notebook.
Ask:
 How do you know when your bridge has collapsed? The bridge will
fall apart or fall down.
8. Say:
 Complete the Handout: Testing Bridges as you are completing the
activity.
9. Discuss the results as a whole class.
EXPLORE/EXPLAIN – Imagine
Suggested Days 3 (continued) and 4
1. Students will work in groups of 3. Each student in the group will complete
the Handout: Imagine.
2. Introduce the activity:
 So far, you have learned about different types of bridges,
examined a variety of materials that you could use to build a
bridge, and tested two bridge designs. Now, you are going to use
your imagination, your knowledge of science and creativity to
design a bridge.
3. Explain that the data recording sheet, Handout: Imagine, is their personal
design for a bridge. Their design may only incorporate the materials they
explored in the plastic bag. (Remind students to refer to the chart that was
completed in class.) Students should be able to justify the selection of the
materials they choose for their design based on their physical properties.
This is an individual plan. In the next lesson they will work as a team to
compare and evaluate plans and then decide on a group plan.
Materials:
 glue (sticks or white liquid, per
group)
Attachments:
 Handout: Imagine (1 per student)
Misconception:
 Students may think that only adults
can design structures.
4. Distribute the Handout: Imagine. Students should only be using a pencil for Science Notebooks:
Students should complete the Handout:
this design (no crayons or colored pencils).
Imagine. Glue into science notebook.
EXPLAIN/ ELABORATE – Our Plan
Suggested Days 5 and 6
1. Tell students that they are now going to complete a design challenge about
building a bridge.
Say:
Materials:
 There will be some rules and requirements you will all need to follow for  toothpicks (for bridges, see Advance
©2012, TESCCC
06/05/13
page 5 of 7
Grade 2
Science
Unit: 02 Lesson: 03
Instructional Procedures
a.
b.
c.
d.
e.
f.
g.
h.
i.
j.
Notes for Teacher
this challenge. You will need to listen carefully. I will also write the rules
and requirements on a chart. (These rules are also on the Handout:
Rules and Requirements for Bridge Design Challenge.)
You will work in teams of three.
Each group member will show his or her Imagine plan and describe the
strengths of their design to the team.
Your team will decide on ONE plan for a bridge design based on all
three plans you have evaluated.
Your team will draw and label one design for a bridge. This will be the
design you will build and test.
You may use the kinds of materials you tested for physical properties.
You will have a limited amount of tape available.
Your design must indicate how much of each material you will need—
for example: if I used straws, I would have to say how many straws my
design needs.
Your bridge must span a distance of 15 inches (38cm), be about 6
inches (15cm) off the ground, and support a load of (20 pennies).
The bridge will be tested using a cup with weights.
Groups will receive only the amount of materials listed on their plan;
they will bring their plan to the materials table, and the teacher will
measure or count out the materials.
2. Ask:
 Are there any questions? Answer all student questions about the
challenge.
3. Remind students that their groups will be building the designs they draw.







Preparation, per group)
craft sticks (for bridges, see Advance
Preparation, per group)
non-flexible straws or coffee stirrers
(for bridges, see Advance
Preparation, per group)
string (for bridges, see Advance
Preparation, per group)
paper clips (for bridges, see
Advance Preparation, per group)
index cards (5”x7”, for bridges, see
Advance Preparation, per group)
paper (drawing, for bridges, see
Advance Preparation, per group)
Tape (for bridges, see Advance
Preparation, per group)
Attachments:
 Handout: Our Plan (1 per group)
 Handout: Rules and Requirements
for Bridge Design Challenge
 Handout: Exploring Physical
Properties (from previous activity) (1
per student)
 Teacher Resource: Exploring
Physical Properties- Sample KEY
Instructional Notes:
The load that the bridge needs to
support will be determined by the
teacher. 20 pennies is reasonable for
this activity, but substitute any weights
5. Students should communicate their ideas to each other before drawing their you have available.
plan.
The most difficult aspect of this activity is
6. Students will now work in their groups to plan, design and draw their bridge not assisting students with their design
design. (Only one student from each group will come to the materials table or the construction of the bridge.
4. Distribute the Handout: Our Plan to each group. It is suggested that
students only use pencils—no crayons or colored pencils. Remind them
that they will not receive any materials to build their design until a complete
plan, including labels, is submitted.
to gather the materials listed on their plan.)
7. Encourage students to work carefully. They have two days to plan and build
their bridge.
EVALUATE – Performance Indicator - Testing the Bridges
1. Refer to the Teacher Resource: Instructions for Performance Indicator
for information on administering the performance assessment.
EVALUATE – Performance Indicator - A Final Report
©2012, TESCCC
06/05/13
Suggested Day 7
Attachments:
 Teacher Resource: Instructions for
Performance Indicator
Suggested Day 8
page 6 of 7
Grade 2
Science
Unit: 02 Lesson: 03
Instructional Procedures
Notes for Teacher
Performance Indicator
 In small groups, design and build a bridge that can span a distance of 15
inches (38cm) be about 6 inches (15 cm) off the ground, and support a
load (determined by the teacher). Justify the selection of materials based
on their physical properties. Communicate the results of the investigation
by recording in science notebooks using pictures and words. (2.2B,
2.3A, 2.5D)
1E; 3E; 5B
Materials:
 pencils (1 per student)
1. Refer to the Teacher Resource: Instructions for Performance Indicator
for information on administering the performance assessment.
Attachments:
 Handout: A Final Report (1 per
student)
 Teacher Resource: Instructions for
Performance Indicator
Science Notebooks:
After completing A Final Report,
students should glue it into their science
notebook.
©2012, TESCCC
06/05/13
page 7 of 7