few_shots: 
Example 1:
Concept/skill: 
Prove the addition and subtraction formulas for sine, cosine, and tangent and use them to solve problems.

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


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:
Concept/skill: 
Solve quadratic equations in one variable.

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


Answer: 
Yes. This task shows one quadratic equation with one variable, x.

Example 3:
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.

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 $P$.


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, assess whether the following problem or activity is 'aligned' with the given Common Core standard in Mathematics.

shot_info: fl_problem_001894_pos_0

HS_0

im_task_000870_pos_0

HS_1

im_task_001160_pos_0

HS_2
standard_description: Add within 100, including adding a two-digit number and a one-digit number, and adding a two-digit number and a multiple of 10, using concrete models or drawings and strategies based on place value, properties of operations, and/or the relationship between addition and subtraction; relate the strategy to a written method and explain the reasoning used. Understand that in adding two-digit numbers, one adds tens and tens, ones and ones; and sometimes it is necessary to compose a ten.
problem_activity: Narrative
The purpose of this activity is for students to represent on paper the class data collected during the previous activity. Students determine how they want to represent their data which was represented by cubes in the previous activity. Representations may include squares (as cubes), tally marks, or number symbols. Students also label their representations.
Required Materials
Materials to Gather
Colored pencils or crayons
Connecting cubes
Materials from a previous activity
Required Preparation
Have extra copies of the three-column table from a previous lesson available for students.
Launch
Groups of 2
Give each group access to colored pencils or crayons and copies of the three-column table.
“We have to put the cubes away at the end of math, but we want to be able to see our class data tomorrow. With your partner, come up with a plan to show our data on paper.”
3 minutes: partner discussion
Activity
“Now each of you will show our class data on paper.”
10 minutes: independent work time
As students work, consider asking questions to help clarify representations:
“Which category is this? What can you do so others can tell what each category is on your paper?”
“What is the title of your data representation?”
Monitor for different representations that use squares, tally marks, and numbers to share during the synthesis of the next activity.
Student Facing
Show the survey data about our class’s favorite
___________________________________________________.
Student Response
Teachers with a valid work email address can
click here to register or sign in
for free access to Student Response.
Activity Synthesis
“Now let’s see what we can learn about the representations of our class data.”


aligns: no