Lesson 1: Thinking about How Things Change

2nd Grade Balance and Motion Unit Blueprint—Investigation 1: Balance

Pacing Suggestions (45-60 minute lessons):

Day 1—Part 1: Trick Crayfish
Days 2 & 3—Part 2: Triangle and Arch
Day 4—Part 3: The Pencil Trick
Day 5—Make It Balance! FOSS Science Story
Day 6—Part 4: Mobiles

Teacher Resources:
	Trick Crayfish Lab Sheets (Adobe^® Reader^® PDF) Triangle and Arch Lab Sheets (Adobe Reader PDF) The Pencil Trick Lab Sheets (Adobe Reader PDF) Mobiles Lab Sheets (Adobe Reader PDF)	Trick Crayfish Lab Sheets (Microsoft^® Word^®) Triangle and Arch Lab Sheets (Microsoft Word) The Pencil Trick Lab Sheets (Microsoft Word) Mobiles Lab Sheets (Microsoft Word)

Essential & Unit Questions ¹

Benchmarks ²

Formative and Summative Assessments ³

Using Assessments to Monitor Student Learning

What is necessary to keep an object from falling to the ground?

4G(K-2)#1: Things near the earth fall to the ground unless something holds them up.

All Activities

Class discussion about the observation that objects in a stable balancing position do not fall to the ground

Trick Crayfish Lab Book Question

Answer to student lab book question "How do you know when the crayfish is balanced?"
(Lab sheet available under "Teacher Resources" section)

Triangle and Arch worksheet

Stable Positions worksheet
Note: The emphasis of this worksheet should be on seeing the relationship between the balance point and counterbalances.

All Activities

Are the students able to express discoveries made about balance, stability, and counterbalance during discussions?
Can students describe where to place counterbalances in order to balance a system?
Do student know that the object will fall if the balance point is not supported?

Trick Crayfish Lab Book Question

Do students write that the crayfish doesn't fall down?

Triangle and Arch worksheet

Do students know what a stable system is?
Are students able to correctly identify the shapes that are balanced?

What are some descriptions of the way things move?

4F(K-2)#1: Things move in many different ways, such as straight, zigzag, round and round, back and forth, and fast and slow.

All Activities

Class discussions/observations about how balanced objects move when pushed

Triangle and Arch

Student lab book question: If a shape is balanced, how does it move when given a slight push? (Lab sheet available under "Teacher Resources" section)

Make It Balance! FOSS Science Story

Class discussion about the different ways things move (Questions refer to text on page 3 in book):
- What are some things that move from one place to another?
- What are some things that spin around and around?

All Activities & Triangle and Arch Lab Book Question

Do students know that balanced objects wobble or rock back and forth when gently pushed?

Make It Balance! FOSS Science Story

Can students give examples of things that move from one place to another? (Examples: people and animals)
Can students give examples of things that spin around and around? (Examples: merry-go-round, yo-yo, mixer)

What are parts? Why are parts important for some things?

11A(K-2)#2: Something may not work if some of its parts are missing

11A(K-2)#3 When parts are put together, they can do things that they couldn't do by themselves.

All Activities

Class discussions about how the addition of parts (counterweights) allows the objects to balance.

Note: To address the benchmark the class discussion must include the idea that only when the parts are put together can the objects balance.

Mobiles

Student lab book question: What would happen if you removed one of the parts of the mobile? (Lab sheet available under "Teacher Resources" section)

Class Discussions about All Activities

Do students understand that the objects and counterweights work together to allow an object to balance?
Do students recognize that without the counterweights the objects can't be balanced?

Mobiles Lab Book Question

Do students know that the mobile will not balance properly without all its parts?

12D(K-2)#2: Draw pictures that correctly portray at least some features of the thing being described.

All Activities

Students draw pictures in their lab books of the items balanced with counterweights (Lab sheets available under "Teacher Resources" section)

Note: The FOSS Teacher's Guide does not direct the teacher to have students draw pictures of the various systems. This is a valuable experience and has been added to the unit. It also reinforces the benchmarks related to "parts."

Do students make legible drawings?
Do the pictures correctly portray some of the features?
Do the students' drawings contain accurate and complete labels?

Why are models important? How are models like the real thing and how are they different?

11B(K-2)#2: A model of something is different from the real thing but can be used to learn something about the real thing.

Mobiles

Class discussion about how the students' model mobiles are alike and different from the real thing. Ask students what we can learn from a model mobile.

Note: The lesson as written in the Teacher's Guide does not address this benchmark. As part of the "Wrapping Up" session, teachers can incorporate these ideas in the class discussion.

Are students able to identify similarities between their model mobiles and real ones? (Example: have balanced items hanging from them)
Are students able to identify differences between their model mobiles and real ones? (Example: real ones move and some have motors)
Can students articulate what they learned from their models? (Example: how to balance multiple items)

For conceptual benchmarks.
Bolded Sections indicate portion of benchmark addressed.
Unless noted as a Summative Assessment, the assessments are formative and should be used to guide teaching and learning.