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, 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_neg_0

HS_1

im_task_001160_pos_0

HS_2
standard_description: Interpret whole-number quotients of whole numbers, e.g., interpret 56 ÷ 8 as the number of objects in each share when 56 objects are partitioned equally into 8 shares, or as a number of shares when 56 objects are partitioned into equal shares of 8 objects each. For example, describe a context in which a number of shares or a number of groups can be expressed as 56 ÷ 8.
problem_activity: Narrative
The purpose of this activity is for students to see how, when multiplying a number larger than ten, the distributive property can be used to decompose the factor into tens and ones, creating two smaller products. Base-ten blocks are used to help students visualize what is happening when a factor is decomposed to make two more easily known products. Factors slightly larger than ten can be naturally decomposed into a ten and some ones using place value. This will be useful in subsequent lessons as students progress towards fluent multiplication and division within 100.
When students see that you can decompose a teen number into tens and ones and use this to multiply teen numbers, they look for and make use of structure (MP7).
Required Materials
Materials to Gather
Base-ten blocks
Launch
Groups of 2
Give students base-ten blocks.
Activity
“Take a few minutes to look at Tyler’s strategy and decide if you agree or disagree with it.”
2–3 minutes: independent work time
3–4 minutes: partner discussion
Monitor for students who connect the expressions
\(7 \times 10\)
and
\(7 \times 3\)
to the tens and ones portion of the place value diagram and
\(7 \times 13\)
to the entire diagram.
Have students share why they agreed or disagreed with Tyler’s strategy with a focus on using the place value diagram as a justification.
Consider asking:
“Where do we see the
\(7 \times 13\)
in the place value diagram?”
“Where do the 10 and the 3 come from?”
“How could you use the place value diagram to figure out how to find the value of
\(7 \times 13\)
?”
“Now use Tyler’s method on your own to find the value of
\(3 \times 14\)
.”
2–3 minutes: independent work time
“Share your solution and your reasoning with your partner.”
2–3 minutes: partner discussion
Student Facing
Tyler says he can use base-ten blocks to find the value of
\(7 \times 13\)
because he knows
\(7 \times 10\)
and
\(7 \times 3\)
. He says this diagram proves his thinking.
Do you agree or disagree? Explain your reasoning.
[IMG]
Use Tyler’s method to find the value of
\(3 \times 14\)
. Explain or show your reasoning.
Student Response
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Advancing Student Thinking
If students say they don’t see
\(7\times10\)
and
\(7\times3\)
in Tyler's diagram, consider asking:
“Where do you see
\(7\times13\)
in the diagram?”
“If we separate the tens and ones, what expression could we use to describe the tens? The ones?”
Activity Synthesis
Display base-ten blocks or place value diagrams that students used to solve. As students explain their work, write multiplication expressions to represent them.
“How does this diagram (or the base-ten blocks) show how Tyler’s method could be used to multiply
\(3 \times 14\)
?” (We can see there are 3 tens which is 30. We can see that there are 3 groups of 4 ones which is 12.
\(30 + 12\)
is 42. The whole diagram represents
\(3 \times 14\)
.)
If there is time, ask students to find the value of
\(4 \times 12\)
and
\(5 \times 16\)
using the base-ten blocks and Tyler’s strategy.


aligns: no