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


Concept/skill: 
Understand that by similarity, side ratios in right triangles are properties of the angles in the triangle, leading to definitions of trigonometric ratios for acute angles.

Answer: 
No. This problem does not directly teach how side ratios in right triangles lead to definitions of trigonometric ratios. Instead, it involves solving a trigonometric function.

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

shot_info: fl_problem_001894_neg_0

HS_0

im_task_000870_neg_0

HS_1

im_task_001160_pos_0

HS_2
standard_description: Apply and extend previous understandings of multiplication to multiply a fraction or whole number by a fraction.
problem_activity: Narrative
The purpose of this activity is for students to relate multiplying a non-unit fraction by a whole number to multiplying a unit fraction by the same whole number. After finding the value of
\(\frac{1}{5} \times 3\)
in a way that makes sense to them, they then consider the value of the products
\(\frac{2}{5} \times 3\)
and
\(\frac{3}{5} \times 3\)
. In the synthesis students address how they can use the value of
\(\frac{1}{5} \times 3\)
to find the value other expressions.
Launch
Groups of 2
Activity
8 minutes: independent work time
Monitor for students who:
draw a diagram
use division to solve
recognize a relationship between
\(\frac{1}{5}\times3\)
,
\(\frac{2}{5}\times3\)
, and
\(\frac{3}{5}\times3\)
.
Student Facing
Find the value of each expression. Explain or show your reasoning. Draw a diagram if it is helpful.
\(\frac{1}{5} \times 3\)
\(\frac{2}{5} \times 3\)
\(\frac{3}{5} \times 3\)
Student Response
Teachers with a valid work email address can
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for free access to Student Response.
Activity Synthesis
Ask previously selected students to share their solutions.
Display:
\(\frac{1}{5} \times 3\)
,
\(\frac{2}{5} \times 3\)
,
\(\frac{3}{5} \times 3\)
“How are the expressions the same?” (They all have a 3. They all have some fifths and there is a product.)
“How are the expressions different?” (The number of fifths is different. There is 1 and then 2 and then 3.)
“How can you use the value of
\(\frac{1}{5} \times 3\)
to help find the value of
\(\frac{2}{5} \times 3\)
?” (I can just double the result because it’s
\(\frac{2}{5}\)
instead of
\(\frac{1}{5}\)
.)
“What about
\(\frac{3}{5} \times 3\)
?” (That’s just another
\(\frac{1}{5} \times 3\)
.)
Display diagram from student solution or a student generated diagram like it.
“How does the diagram show
\(\frac{1}{5} \times 3\)
?” (There is 3 total and
\(\frac{1}{5}\)
of it is shaded.)
Display:
\(\frac{2}{5} \times 3\)
.
“How could you adapt the diagram to show
\(\frac{2}{5} \times 3\)
?” (I could fill in 2 of the fifths in each whole instead of 1.)
“In the next activity we will study a diagram for
\(\frac{2}{5} \times 3\)
more.”


aligns: yes