few_shots: 
Example 1:
Problem/activity:
Find the general solution for:
$${\mathrm{cos}\left({\pi\over2}+x\right)=\mathrm{tan}{\pi\over4}}$$


Concept/skill: 
Prove the addition and subtraction formulas for sine, cosine, and tangent and use them to solve problems.

Answer: 
Yes. 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.

Example 2:
Problem/activity:
Task
Solve the quadratic equation
$$ x^2 = (2x - 9)^2 $$
using as many different methods as possible.


Concept/skill: 
Understand that the graph of an equation in two variables is the set of all its solutions plotted in the coordinate plane, often forming a curve (which could be a line).

Answer: 
No. This task does not involve an equation in two variables. There is only one variable, x.

Example 3:
Problem/activity:
Task
Suppose $A$ is an angle with vertex $P$, as pictured below:
[IMG]
Draw a circle with center $P$ and with  radius $r \gt 0$.  Explain why the circle
meets each ray of angle $A$ in a single point.  Label these points $Q$ and $R$ respectively.
Draw circles with centers $Q$ and $R$ respectively and radius $r$.  These circles meet at $P$ and a second point to be labelled $B$.
Show that ray $\overrightarrow{PB}$  bisects angle $P$.


Concept/skill: 
Make formal geometric constructions with a variety of tools and methods (compass and straightedge, string, reflective devices, paper folding, dynamic geometric software, etc.). Copying a segment; copying an angle; bisecting a segment; bisecting an angle; constructing perpendicular lines, including the perpendicular bisector of a line segment; and constructing a line parallel to a given line through a point not on the line.

Answer: 
Yes. This task asks students to draw a ray that bisects an angle. The act of drawing circles and rays may involve compass and straightedge or dynamic geometric software.

Now, does the problem or activity shown below enable students to learn the full intent of the following concept or skill?

shot_info: fl_problem_001894_pos_0

HS_0

im_task_000870_neg_0

HS_1

im_task_001160_pos_0

HS_2
standard_description: Represent whole numbers as lengths from 0 on a number line diagram with equally spaced points corresponding to the numbers 0, 1, 2, ..., and represent whole-number sums and differences within 100 on a number line diagram.
problem_activity: Narrative
The purpose of this activity is for students to make sense of different methods they can use to compare three-digit numbers. They analyze the thinking of others and make connections across representations (MP2, MP3). Although students have compared numbers using different representations in prior units, this activity offers them the opportunity to consider using the number line as a tool to compare three-digit numbers. In the synthesis, students will discuss which representation makes it easier to see the comparison. While students could make a case that each of the representations was easier for them, the focus is on Jada’s way, the number line.
MLR8 Discussion Supports.
Display sentence frames to support partner discussion. “_____ and _____ are the same/alike because . . .” and “_____ and _____ are different because . . . .”
Advances: Speaking, Conversing
Launch
Groups of 2
Activity
“Diego, Jada, and Clare were asked to compare 371 and 317. They each represented their thinking differently.”
“Take some time to look over their methods.”
2 minutes: independent work time
“Discuss with your partner how their methods are the same and different.”
4 minutes: partner discussion
“Now try Jada’s way.”
6 minutes: partner work time
Student Facing
Each student compared 371 and 317, but represented their thinking in different ways.
Diego
[IMG]
[IMG]
I see 3 hundreds for each number.
317 only has 1 ten, but 371 has 7 tens.
\(371 > 317\)
Clare
Each has 3 hundreds.
371 has 7 tens, but 317 only has 1 ten.
\(317 < 371\)
Jada
[IMG]
I can see that 371 is farther to the right on my number line, so I know it is greater than 317.
\(371 > 317\)
What is the same and different about these students’ representations?
Discuss with a partner.
Try Jada’s way.
Estimate the location of 483 and 443 on the number line.
Mark each number with a point. Label the point with the number it represents.
[IMG]
Use
\(>\)
,
\(=\)
, or
\(<\)
to compare 483 and 443.
______________________________
Student Response
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for free access to Student Response.
Advancing Student Thinking
If students write comparison statements that are not true, ask them to read their statements and consider asking:
“How did you decide which number was greater?”
“How does your statement match the number line?”
Activity Synthesis
“Clare, Diego, and Jada represented their thinking in different ways. Whose method made it easier to see that 371 is greater than 317? Explain.” (Jada’s because you just have to look at which number is farther to the right. You can see 371 is farther from 0. Diego’s because I use diagrams and I can see quickly that the hundreds are the same and there are more tens, but some things were the same.)
As needed, “Jada and Diego wrote
\(371 > 317\)
, but Clare wrote
\(317 < 371\)
. Who do you agree with? Explain.” (They both mean the same thing. 371 is greater than 317, so 317 is less than 371.)


aligns: yes