few_shots: Example 1:
Problem/activity:
Task
Materials
One 10-frame per pair of students (see example below)
[IMG]
Counters, 10 per pair of students
Decks of number cards 0-5 (with 4 of each number) or two 0-5 dice
Setup
This activity is done in pairs. The students sit side by side with 10-frame and deck of cards or dice. If they have cards, the cards are shuffled and placed face down in front of them.
Action
Player 1 flips a card or rolls the die. They place that many counters on the 10-frame. Player 2 flips a card or rolls the die. They place that many more counters on the 10-frame next to the counters already on the ten frame. The students count the total together.
A recording sheet can be added when the students have been introduced to equations and number sentences. For those students who can handle higher numbers, a deck of 0-10 cards and two 10-frames can be used.
This game can also be played alone.


Standard options: 
A. Represent addition and subtraction with objects, fingers, mental images, drawings (Drawings need not show details, but should show the mathematics in the problem. (This applies wherever drawings are mentioned in the Standards.)), sounds (e.g., claps), acting out situations, verbal explanations, expressions, or equations.
B. For any number from 1 to 9, find the number that makes 10 when added to the given number, e.g., by using objects or drawings, and record the answer with a drawing or equation.
C. Decompose numbers less than or equal to 10 into pairs in more than one way, e.g., by using objects or drawings, and record each decomposition by a drawing or equation (e.g., 5 = 2 + 3 and 5 = 4 + 1).
D. Solve addition and subtraction word problems, and add and subtract within 10, e.g., by using objects or drawings to represent the problem.
E. Fluently add and subtract within 5.


Thought: This task involves representing addition with objects such as number cards and dice.
Answer: A

Example 2:
Problem/activity:
For each pair of numbers, determine if the values are equivalent. Explain your reasoning for each one.
a.
$$-0.25$$
and
$$\frac{1}{-4}$$
b.
$$-\left ( \frac{1}{4} \right )$$
and
$$\frac{-1}{-4}$$
c.
$$\frac{-1}{4}$$
and
$$-\frac{1}{4}$$


Standard options: 
A. Solve real-world and mathematical problems involving the four operations with rational numbers. (Computations with rational numbers extend the rules for manipulating fractions to complex fractions.)
B. Apply and extend previous understandings of multiplication and division and of fractions to multiply and divide rational numbers.
C. Apply and extend previous understandings of addition and subtraction to add and subtract rational numbers; represent addition and subtraction on a horizontal or vertical number line diagram.


Thought: This problem involves understanding fractions and division to divide rational numbers, such as 1, -4, 4, and -1. This problem also involves an understanding of multiplication: if p and q are integers, then -(p/q) = (-p)/q = p/(-q).
Answer: B

Example 3:
Problem/activity:
Find the general solution for:
$${\mathrm{cos}\left({\pi\over2}+x\right)=\mathrm{tan}{\pi\over4}}$$


Standard options: 
A. Prove the Pythagorean identity sin^(2)(θ) + cos^(2)(θ) = 1 and use it to find sin(θ), cos(θ),or tan(θ) given sin(θ), cos(θ), or tan(θ) and the quadrant of the angle.
B. Prove the addition and subtraction formulas for sine, cosine, and tangent and use them to solve problems.


Thought: An initial step when solving for x in this problem requires the use of the addition formula for cosine on the left side of the equation. Solving this problem does not require use of the Pythagorean identity.
Answer: B

Now, assign the following problem or activity to one or more relevant standards it aligns with.
shot_info: im_task_001477

K

fl_problem_001097

7

fl_problem_001894

HS_0
options: Find the area of right triangles, other triangles, special quadrilaterals, and polygons by composing into rectangles or decomposing into triangles and other shapes; apply these techniques in the context of solving real-world and mathematical problems.

Draw polygons in the coordinate plane given coordinates for the vertices; use coordinates to find the length of a side joining points with the same first coordinate or the same second coordinate. Apply these techniques in the context of solving real-world and mathematical problems.

Represent three-dimensional figures using nets made up of rectangles and triangles, and use the nets to find the surface area of these figures. Apply these techniques in the context of solving real-world and mathematical problems.

Find the volume of a right rectangular prism with fractional edge lengths by packing it with unit cubes of the appropriate unit fraction edge lengths, and show that the volume is the same as would be found by multiplying the edge lengths of the prism. Apply the formulas V = l w h and V = b h to find volumes of right rectangular prisms with fractional edge lengths in the context of solving real-world and mathematical problems.
problem_activity: Activity
This activity gives students opportunities to find areas of regions using a variety of strategies. When working with a grid, students may start by counting squares, as they had done in earlier grades. However, the figures have been chosen to elicit the strategies listed in the Lesson Narrative.
Figure A can be easily decomposed into rectangles.
Figure B can be decomposed into rectangles. Or, more efficiently, it can be seen as a square with a missing piece, and the area of the inner unshaded square can be subtracted from the area of the larger square.
Figure C can also be seen as having a missing piece, but subtracting the area of the unshaded shape does not work because the side lengths of the inner square are unknown. Instead, the shaded triangles can be decomposed and rearranged into rectangles.
Figure D can be decomposed and rearranged into rectangles. It can also be viewed as the inner square of Figure C.
As students work, identify students who use these strategies and can illustrate or explain them clearly. Ask them to share later. Look for at least two strategies being used for each figure (one strategy as shown in the Student Response and at least one other).
Launch
Tell students that they will find the areas of various figures on a grid. To encourage students to use a more grade-appropriate strategy for finding areas, show them a strategy from earlier grades. As a class, find the area of Figure A by counting the squares one by one aloud. Confirm that there are 24 square units, and then ask students to think about other ways to find the area of Figure A and other figures besides counting each square.
Arrange students in groups of 2. Ask one partner to start with Figures A and C, and the other with B and D. Give students 4–5 minutes of quiet think time, and provide access to their geometry toolkits. Then, give them a few minutes to share their responses with their partner. Emphasize that as one partner explains, the other should listen carefully and see if they agree or disagree with the answer and explanations.
Student Facing
Each grid square is 1 square unit. Find the area, in square units, of each shaded region without counting every square. Be prepared to explain your reasoning.
[IMG]
Student Response
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Student Facing
Are you ready for more?
Rearrange the triangles from Figure C so they fit inside Figure D. Draw and color a diagram of your work.
Student Response
Teachers with a valid work email address can
click here to register or sign in
for free access to Extension Student Response.
Anticipated Misconceptions
Some students may count both complete and partial grid squares instead of looking for ways to decompose and rearrange larger shapes. Ask them if they can find a way to to find the area by decomposing and rearranging larger pieces. The discussion at the end, during which everyone sees a variety of strategies, is especially important for these students.
Activity Synthesis
Discussion should center around how different strategies—decomposing, rearranging, subtracting, and enclosing—are used to find area. For each figure, select two students with different strategies to share their work, if possible. Sequence students’ presentations so that, for each figure, a subtracting strategy comes last, as that is typically the most challenging.
Before sharing begins, explain to students that they should notice similarities and differences in the strategies shared and be ready to explain them. As students share their strategies, consider recording the moves on each figure for all to see. After each person shares, name the strategy, and poll the class to see if anyone else reasoned the same way. If one of these strategies does not appear in students’ work, illustrate it for the class.
Decomposing (A and B)
Decomposing and rearranging (C and D)
Subtracting (B)
Enclosing, then subtracting (D)
If time permits, give partners a minute to talk to their partner about the similarities and differences they saw in the strategies used to find the areas of the four figures. Consider displaying sentence starters such as:
The strategies used to find the areas of figures ____ and ____ are alike in that. . .
The strategies used to find the areas of figures ____ and ____ are different in that. . .
Representation: Internalize Comprehension.
Use color and annotations to highlight distinctions between strategies. Create a display that includes multiple copies of each figure. As students describe their strategies, use color and annotation to scribe their thinking so that it is visible for all students. Be sure to label each figure with the strategy described (decomposing, rearranging, subtracting, or enclosing).
Supports accessibility for: Visual-spatial processing; Conceptual processing
Speaking: Math Language Routine 3 Clarify, Critique, Correct.
This is the first time Math Language Routine 3 is suggested as a support in this course. In this routine, students are given an incorrect or incomplete piece of mathematical work. This may be in the form of a written statement, drawing, problem-solving steps, or another mathematical representation. Pairs of students analyze, reflect on, and improve the written work by correcting errors and clarifying meaning. Typical prompts are “Is anything unclear?” or “Are there any reasoning errors?” The purpose of this routine is to engage students in analyzing mathematical thinking that is not their own, and to solidify their knowledge through communicating about conceptual errors and ambiguities in language.
Design Principle(s): Maximize meta-awareness
How It Happens:
In the class discussion for Figure C of this activity, provide the following “draft” explanation:
“I cut a square in the middle, then I saw that it was a bunch of triangles, so then I figured those out to get my answer.”
Prompt students to identify the ambiguity of this response. Ask students, “What do you think this person is trying to say? What is unclear? Did the author use any of the strategies we’ve been using to find area?”
Give students 1 minute of individual time to respond to the questions in writing, and then 3 minutes to discuss with a partner.
As pairs discuss, provide these sentence frames for scaffolding: “I think the author is trying to use the strategy _ because.…”, “I think what the author meant by ‘figured it out’ was….”, and “The part that is most unclear to me is … because.…”. Encourage the listener to press for detail by asking follow-up questions to clarify the intended meaning of the statement. Allow each partner to take a turn as the speaker and listener.
Invite students to improve the “draft” response using the target vocabulary and structures.
The targeted vocabulary includes the names of the strategies (decomposing, rearranging, subtracting, enclosing, or any combination of them), and other terms from this lesson such as “alike,” “different,” “area,” and “polygon.”
The targeted structures of the response should include an explanation of each step, order/time transition words (first, next, then, etc.), and/or reasons for decisions made during steps.
Here is one example of an improved response:
“First, I cut out the square in the middle of the shaded regions. Next, I noticed that all the shaded regions were a bunch of right triangles. Then, I rearranged the triangles into rectangles. Lastly, I figured out the area of each rectangle and added them together to get my answer.”
Ask each pair of students to contribute their improved response to a poster, the whiteboard, or digital projection. Call on 2–3 pairs of students to present their response to the whole class, and invite the class to make comparisons among the responses shared and their own responses.
Listen for responses that include the strategy of decomposing and then rearranging the triangles. Emphasize that this is one way of figuring out the area of the shaded region.
Share one more improved response, discuss to reach a general understanding, and then move on to Figure D.


correct_option_index: 0