few_shots: 
Example:
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.

Now, determine whether the following problem or activity can enable students to understand the concepts or skills in the provided description.

shot_info: fl_problem_001894_pos_0

HS_0
standard_description: Compose and decompose numbers from 11 to 19 into ten ones and some further ones, e.g., by using objects or drawings, and record each composition or decomposition by a drawing or equation (e.g., 18 = 10 + 8); understand that these numbers are composed of ten ones and one, two, three, four, five, six, seven, eight, or nine ones.
problem_activity: Narrative
The purpose of this activity is for students to match equations to numbers 11–19 presented on 10-frames. During the synthesis, students focus on each part of the equation and where it can be seen in the 10-frame representation of the number. When students see different parts of the equations in the 10-frame images, they look for and make use of structure (MP7).
Launch
Groups of 2
“Draw a line from each equation to the dots it matches.”
Activity
2 minutes: independent work time
3 minutes: partner work time
Student Facing
[IMG]
[IMG]
[IMG]
\(10+9=19\)
\(10+1=11\)
\(10+4=14\)
\(10+8=18\)
\(10+5=15\)
\(10+2=12\)
[IMG]
[IMG]
[IMG]
Student Response
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Activity Synthesis
Invite a student to share which image matches
\(10 + 5 = 15\)
.
“Where do you see 15 on the 10-frame?” (There are 15 dots altogether.)
“Where do you see
\(10 + 5\)
on the 10-frame?” (There are 10 dots on the 10-frame and 5 dots under the 10-frame.)


aligns: yes