Javier Builds a Bridge / To Get To The Other Side:Building Bridges

NSF, S.D.Bechtel Jr. Foundation, Liberty Mutual Foundation, Cargill Foundation, Cisco Systems Foundation, & Intel Foundation Museum of Science, Boston Engineering is Elementary
Type Category
Instructional Materials Assessment Materials
Lesson/Lesson Plan , Instructor Guide/Manual , Informative Text , Activity , Assessment Item , Rubric
This resource, vetted by NSTA curators, is provided to teachers along with suggested modifications to make it more in line with the vision of the NGSS. While not considered to be “fully aligned,” the resources and expert recommendations provide teachers with concrete examples and expert guidance using the EQuIP rubric to adapted existing resources. Read more here.



To Get to the Other Side: Designing Bridges is an engineering unit from EIE and The Museum of Science in Boston geared towards Grades 1-5.  Students will be building upon their knowledge of pushes and pulls as they explore how force and balance act upon different structures; as well incorporating the engineering process to design a strong, stable bridge. Modifications and extensions are included for upper elementary students in grades 3-5.  Students will be introduced to the storybook Javier Builds a Bridge where they will learn about the role of civil engineers, various types of bridges, and how Javier solves a problem using the steps of the Engineering Design Process.  Each of the four (4) lessons in this unit build upon the previous lesson.  Lesson one (1) focuses on the role of civil engineers in designing structures and the problems, criteria, constraints and solutions associated with building bridges.  Lesson two (2) focuses on forces that can increase the strength/stability of a structure.  Lesson three (3) activities allow the students to experiment and test three different bridge types, while in lesson four (4) students use what they have learned in the previous lessons to design and implement a bridge design and then test and improve it based on their results. 

Intended Audience

Educational Level
  • Grade 1
  • Grade 2
  • Upper Elementary
Access Restrictions

Available for purchase - The right to view, keep, and/or download material upon payment of a one-time fee.

Performance Expectations

3-5-ETS1-1 Define a simple design problem reflecting a need or a want that includes specified criteria for success and constraints on materials, time, or cost.

Clarification Statement: none

Assessment Boundary: none

This resource is explicitly designed to build towards this performance expectation.

Comments about Including the Performance Expectation
In the storybook Javier Builds a Bridge, Javier is challenged to find a way to make a safer bridge leading to his fort, which is located on an island. With help from his cousins and family, Javier brainstorms and comes up with new bridge ideas using the Engineering Design Process. In the culminating lesson of the unit, the students will use science concepts they learned about balanced forces and the three different types of bridges to design a bridge with specific: constraints (only certain materials to work with) and criteria (a barge must be able to sail underneath the bridge, it should be stable so cars can roll across it, and it must span a gap). Instructions are included with suggestions for upper elementary students to be given a larger gap as well as other tips for advanced learners.

3-PS2-1 Plan and conduct an investigation to provide evidence of the effects of balanced and unbalanced forces on the motion of an object.

Clarification Statement: Examples could include an unbalanced force on one side of a ball can make it start moving; and, balanced forces pushing on a box from both sides will not produce any motion at all.

Assessment Boundary: Assessment is limited to one variable at a time: number, size, or direction of forces. Assessment does not include quantitative force size, only qualitative and relative. Assessment is limited to gravity being addressed as a force that pulls objects down.

This resource appears to be designed to build towards this performance expectation, though the resource developer has not explicitly stated so.

Comments about Including the Performance Expectation
Throughout the four (4) lesson unit, students have opportunities to provide evidence that the position and motion of an object can be changed by a push or a pull; and when all forces acting on a structure are balanced, the structure in is a state of equilibrium. It is suggested that the teacher continually refer back to the Javier's problem from the story that needs to be solved and explore questions with students: How do equal and unequal forces on an object affect the bridge that Javier is designing and building? To best meet the full text of the performance expectation it is suggested that students plan investigations or ideas that they can test about balanced and unbalanced forces. Students can experiment with balanced forces pushing on a box from both sides to show no motion at all. They can then plan to move another object, pushing it from one side to investigate unbalanced forces.

Science and Engineering Practices

This resource appears to be designed to build towards this science and engineering practice, though the resource developer has not explicitly stated so.

Comments about Including the Science and Engineering Practice
When reading the storybook, the teacher could point out scientific concepts that are relevant to the design process (such as the properties of the materials used). In one of the lessons, the students will be conducting a controlled experiment that will determine and compare the strength of three different bridge types: beam, arch, and deep beam).

Disciplinary Core Ideas

This resource is explicitly designed to build towards this disciplinary core idea.

Comments about Including the Disciplinary Core Idea
In each of the lessons in this unit the students apply concepts that will help them explain that when they apply a new force in the opposite direction of an existing force. it can increase the strength and stability of their structures. In Lesson two students will be identifying some of the forces (pushes and pulls) that act on their structures. They will investigate how two equal forces that act on their structures in opposite directions will balance one another out.

Crosscutting Concepts

This resource appears to be designed to build towards this crosscutting concept, though the resource developer has not explicitly stated so.

Comments about Including the Crosscutting Concept
The functioning of a bridge depends on the shapes and relationship of certain key parts of the bridge. A bridge is a structure that spans horizontally between supports, whose function is to carry vertical loads. It is recommended to discuss with students how the supports must be strong enough to hold the structure up, and the span between supports must be strong enough to carry the loads.

This resource appears to be designed to build towards this crosscutting concept, though the resource developer has not explicitly stated so.

Comments about Including the Crosscutting Concept
During this unit students identify and test the structure of three different bridge types (beam, arch, and deep beam). Through experimentation, students brainstorm how using different materials (paper) and changing it's shape, can distribute forces in different directions. It is suggested to reiterate the cause and effect relationship through questioning. When students ask, "Why did that happen?" and "How did that happen?" they are guided to ask themselves "What did they change that caused that to happen?" or "What conditions were important for that to happen?"

Resource Quality

  • Alignment to the Dimensions of the NGSS: The high quality of the storybook along with the lessons of this unit provide the student ample opportunities to demonstrate proficiency in forces, balance and stability when designing a solution to the problem of designing a bridge. The three dimensions work together to support the students as they make sense of designing and testing structures that are stable and strong. From the initial story of Javier's bridge design problem to the culminating engineering design challenge, each of the lessons link together building upon the previous lessons allowing the students to use what they learned about the engineering field as well as the balance and distribution of the forces acting on bridges.

  • Instructional Supports: This unit provides a plethora of information to guide teachers on implementing each of the four (4) lessons. Each lesson and activity builds on the next with guiding questions, clear obtainable student objectives, an overview of what the student will be able to explain after the activity, background knowledge, materials needed, teacher tips for differentiated learners, advanced lessons, assessments, rubrics and reflection questions. Ideas for extension and reinforcement are included at the end of each lesson. Advanced students could research the bridges discussed in the story to locate similar bridges across the country and discuss evidence for why they think the bridge was built where it was and list materials they think were used giving evidence for their choices. This could be incorporated through a writing activity task which would give the students ownership and input for their ideas. With the help of a city planner or civil engineer mentor, students could locate, visit, or view photos of bridges in their own area, discussing structure, need, and materials used in bridge design.

  • Monitoring Student Progress: This unit provides multiple opportunities for students to demonstrate their understanding of what civil engineers need to think about when designing bridges. Guided questions for each activity are embedded throughout with answers to help guide instructors to assess student understanding. Rubrics to assess what students will be able to do after each activity are included as well as opportunities for students to draw and explain diagrams showing how forces act on structures. It is suggested while reading the story of Javier, the teacher could stop and question students as to what they think a civil engineer does, and how his/her job affects community life. Students could devise their own questions that would be appropriate for an interview with a civil engineer after they have created their own bridges to assess the students bridge building progress. Teachers could invite a civil engineer to visit the class to answer questions, share knowledge and provide mentoring and guidance while monitoring students as they create their own bridges. If logistically feasible, a field trip to local small bridges so students can see real life community connections to the needs and structures of the types of bridges they worked with in the unit.

  • Quality of Technological Interactivity: This resource does not contain technological interactivity.