This unit builds toward the following NGSS Performance Expectations (PEs):

• 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.
• 3-PS2-2: Make observations and/or measurements of an object’s motion to provide evidence that a pattern can be used to predict future motion.
• 3-PS2-3: Ask questions to determine cause and effect relationships of electric or magnetic interactions between two objects not in contact with each other.
• 3-PS2-4: Define a simple design problem that can be solved by applying scientific ideas about magnets.
• 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.
• 3-5-ETS1-3: Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved.

This unit builds towards the following Disciplinary Core Ideas (DCIs):

PS2.A Force and Motion 

• Each force acts on one particular object and has both strength and a direction. An object at rest typically has multiple forces acting on it, but they add to give zero net force on the object. Forces that do not sum to zero can cause changes in the object’s speed or direction of motion. 

PS2.A Force and Motion

• The patterns of an object’s motion in various situations can be observed and measured; when that past motion exhibits a regular pattern, future motion can be predicted from it.

PS2.B Types of Interaction

• Objects in contact exert forces on each other.
• Electric and magnetic forces between a pair of objects do not require that the objects be in contact. The sizes of the forces in each situation depend on the properties of the objects and their distances apart and, for forces between two magnets, on their orientation relative to each other.

ETS1.A Defining and Delimiting Engineering Problems

• Possible solutions to a problem are limited by available materials and resources (constraints). The success of a designed solution is determined by considering the desired features of a solution (criteria).

ETS1.B Developing Possible Solutions

• Tests are often designed to identify failure points or difficulties, which suggest the elements of the design that need to be improved.

ETS1.C Optimizing the Design Solution

• Different solutions need to be tested in order to determine which of them best solves the problem, given the criteria and the constraints.

This unit intentionally develops students’ engagement in these practice elements:

Asking Questions and Defining Problems

• Ask questions about what would happen if a variable is changed. (AQDP-E1)
• Identify scientific (testable) and non-scientific (non-testable) questions. (AQDP-E2)
• Ask questions that can be investigated and predict reasonable outcomes based on patterns such as cause and effect relationships. (AQDP-E3)
• Define a simple design problem that can be solved through the development of an object, tool, process, or system and include several criteria for success and constraints on materials, time, or cost. (AQDP-E5)

Developing and Using Models

• Collaboratively develop and/or revise a model based on evidence that shows the relationships among variables for frequent and regularly occurring events. (MOD-E2)
• Develop a model using an analogy, example, or abstract representation to describe a scientific principle or design solution. (MOD-E3)
• Develop and/or use models to describe and/or predict phenomena. (MOD-E4)
• Develop a diagram or simple physical prototype to convey a proposed object, tool, or process. (MOD-E5)
• Use a model to test cause and effect relationships or interactions concerning the functioning of a natural or designed system. (MOD–E6)

Planning and Carrying Out Investigations

• Plan and conduct an investigation collaboratively to produce data to serve as the basis for evidence, using fair tests in which variables are controlled and the number of trials considered. (INV-E1)
• Make observations and/or measurements to produce data to serve as the basis for evidence for an explanation of a phenomenon or test a design solution. (INV-E3)
• Make predictions about what would happen if a variable changes. (INV-E4)

In this unit, there are opportunities to practice the following Science and Engineering Practices:

• Analyzing and Interpreting Data
• Constructing Explanations and Designing Solutions
• Obtaining, Evaluating, and Communicating Information

This unit intentionally develops students’ engagement in these Crosscutting Concepts:

Patterns

• Patterns of change can be used to make predictions. (PAT-E2)
• Patterns can be used as evidence to support an explanation. (PAT-E3)

Cause and Effect

• Cause-and-effect relationships are routinely identified, tested, and used to explain change. (CE-E1)

System and System Models

• A system is a group of related parts that make up a whole and can carry out functions its individual parts cannot. (SYS-E1)
• A system can be described in terms of its components and their interactions. (SYS-E2)

In this unit, there are opportunities to practice the following Crosscutting Concepts:

• Scale, Proportion, and Quantity
• Structure and Function

This unit makes these connections to the Nature of Science:

• Science investigations use a variety of methods, tools, and techniques.
• Science is a way of knowing that is used by many people.
• Science findings are based on recognizing patterns.
• Science affects everyday life.
• Science uses tools and technologies to make accurate measurements and observations.
• Creativity and imagination are important to science.

The anchoring phenomenon for this unit is a series of sculptures that balance and move in puzzling ways. These are called balance and kinetic sculptures and are widespread in art and design. Artists design and build these sculptures to balance in odd ways to attract attention from viewers of the art. Sometimes, these sculptures are built using everyday objects and are meant to be temporary. Other times, the sculptures are built to last and may be displayed in a museum or in someone’s personal art collection. Many times these sculptures do not use glue to hold them together, though some balance sculptures do use magnets. Magnetic sculptures may use magnets to create towers of metal art or use forces from magnets to create the appearance that an object is hovering. Artists also design and build kinetic sculptures that are meant to move in interesting ways. Kinetic sculptures are designed to move with the slightest outside force, like a light breeze or a tap of a finger. Kinetic sculptures may be found in museums, art exhibits, outdoor exhibits, homes, and offices. Artists who design and build these sculptures use their knowledge of weight, force, motion, gravity, and magnets to make their sculptures balance and move. This phenomenon was chosen as the unit anchor for the following reasons:

• When elementary students were surveyed about four possible phenomena, balanced art showed the highest interest from students.
• A pilot for a balanced art anchor produced driving question boards and ideas for investigations aligned to the science and engineering ideas to be developed in the unit. Teachers reported high levels of student engagement with the phenomenon.
• A focus on sculptures creates a throughline about art as students developed the science and engineering ideas in the Performance Expectation bundle. The phenomenon also helps to broaden what students may think about who uses science and engineering in their work and lives.
• The sculptures created a context for authentic planning of and carrying out investigations and engaging in engineering design. It allows students to investigate different aspects of the phenomenon and test different variables as they design and build their own sculptures.

This unit is composed of two lesson sets, summarized in the table below.

The goal of integrating literacy within OpenSciEd units is to offer opportunities for practicing reading, writing, speaking, and listening to support science learning. Literacy is fundamental to science because reading, writing, speaking, and listening are the primary means for students to understand and communicate their science ideas. Students use oral (speaking, listening) and written (reading, writing) language to communicate their science ideas and to support their ongoing science sensemaking. Literacy integration throughout the program also helps students learn how to use their oral and written language in a way that mirrors the work of scientists and engineers. The unit teacher materials contain tables that explain the different types of books and texts that students will engage with across the unit to support their sensemaking. 

ELA standards are also integrated throughout the unit to highlight the link between literacy and science for teachers and students. Many ELA standards are incorporated into lessons as needed for specific science learning objectives and teacher guides for those lessons include explicit support for teachers and/or students around connecting to those standards. See the Unit Connections to the Common Core Standards matrix for details about where these specific ELA connection standards happen and how they are used to support the science work in those lessons.

The goal of integrating mathematics in the OpenSciEd units is to build a strong base of knowledge to reinforce and strengthen science learning. Mathematics integration is intentional – to help the storyline along, clarify pieces of the puzzle students are figuring out, or provide students with tools to highlight, analyze, model, and interpret important patterns in the data they are exploring. Mathematical practices (MP2, MP4, MP5, and MP8) along with crosscutting concepts are employed throughout the unit to develop student understanding of science ideas and deepen science practices. In this unit, students will estimate, measure, and calculate values using addition and subtraction to find the weights of objects in grams using digital scales (part of 3.MD.A.2) in Lessons 3, 4, 8, and 11. Students will also add and subtract within 1,000 using strategies and algorithms (part of 3.NBT.A.2) as they work to balance sculptures by calculating the weights of objects in Lessons 3, 4, and 5. See the Teacher Handbook for additional support and differentiation options.

Math standards are incorporated into lessons as needed for specific science learning objectives and teacher guides for those lessons include explicit support for teachers and/or students around connecting to those standards. See the Unit Connections to the Common Core Standards matrix for details about where these specific math standard connections happen and how they are used to support the science work in those lessons. These standards are indicated on that matrix with an asterisk (✱).

• Audrey Mohan, Unit & Field Test Unit Lead, BSCS Science Learning
• Lindsey Mohan, Field Test Unit Lead, BSCS Science Learning
• Amy Morton, Writer, University of Illinois
• Ari Jamshidi, Writer, University of California, Berkeley
• Marsha Turner-Reid, Writer, University of Illinois
• Sue Gaspar, Writer, University of Illinois
• Amanda Dahl, Text Development Lead, Michigan State University
• Carla Robinson, CLS Unit Support The University of Texas at Austin
• Amy Johnson, Math Support, The University of Texas at Austin
• Gretchen Brinza, Coherence Reviewer, Independent Consultant
• Jennifer Pfeifer, Co-Design Teacher, Van Allen Elementary, Chariton CSD, IA
• Kristen Fleming, Co-Design Teacher, Sky Ranch Elementary, Moore, OK
• Betty Stennett, PL Designer and Coherence Reviewer, BSCS Science Learning

• Gen Zoufal, Project Manager, Northwestern University
• Braeden Speight, Copy Editor, Independent Consultant
• Chris Moraine, Graphic Designer, BSCS Science Learning
• Ken Roy, Safety Consultant, National Safety Consultants, LLC

An integral component of OpenSciEd’s development process is external validation of alignment to the Next Generation Science Standards by the NSTA using the EQuIP Rubric for Science. We are proud that this unit has earned the highest score and rating available and has been awarded the NSTA NGSS 3D Design Badge. You can find additional information and read this unit’s review on NSTA’s website.