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: 
Solve quadratic equations in one variable.

Answer: 
Yes. This task shows one quadratic equation with 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, 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: 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 learn stage 2 of the Greatest of Them All center. Students use digit cards to create the greatest possible number. As each student draws a card, they choose where to write it on the recording sheet. Once a digit is placed, it can’t be moved. Students compare their numbers using
\(<\)
,
\(>\)
, or
\(=\)
. The player with the greater number in each round gets a point.
Students should remove cards that show 10 from their deck.
MLR2 Collect and Display.
Synthesis: Direct attention to the words collected and displayed on the anchor chart from the previous lessons. Invite students to borrow place value language from the display as needed.
Advances: Conversing, Reading
Required Materials
Materials to Gather
Number cards 0–10
Materials to Copy
Greatest of Them All Stage 2 Recording Sheet
Launch
Groups of 2
Give each group a set of number cards and each student a recording sheet.
“Now you will be playing the Greatest of Them All center with your partner.”
“You will try to make the greatest three-digit number you can.”
Display number cards and recording sheet.
Demonstrate picking a card.
“If I pick a (2), I need to decide whether I want to put it in the hundreds, tens, or ones place to make the largest three-digit number.”
“Where do you think I should put it?” (I think it should go in the ones place because it is a low number. In the hundreds place, it would only be 200.)
30 seconds: quiet think time
Share responses.
“At the same time, my partner is picking cards and building a number, too.”
“Take turns picking a card and writing each digit in a space.”
“Read your comparison aloud to your partner.”
Activity
“Now play a few rounds with your partner.”
15 minutes: partner work time
Activity Synthesis
Select a group to share a comparison statement. For example:
\(654 > 349 \)
and
\(349 < 654\)
.
“I noticed that partners had different comparison statements for the same numbers. How can they both be true?”
“If I draw an 8, where should I choose to place it and why?” (I would put it in the hundreds place since it’s almost the highest number I could
draw
. I might not get 9. With 800, I have a good chance for my number to be larger than my partner’s.)


aligns: no