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: Partition circles and rectangles into two and four equal shares, describe the shares using the words halves, fourths, and quarters, and use the phrases half of, fourth of, and quarter of. Describe the whole as two of, or four of the shares. Understand for these examples that decomposing into more equal shares creates smaller shares.
problem_activity: Narrative
The purpose of this activity is for students to choose from activities that offer practice adding and subtracting within 10. Students choose from any stage of previously introduced centers.
Shake and Spill
Compare
Number Puzzles
Required Materials
Materials to Gather
Materials from previous centers
Required Preparation
Gather materials from previous centers:
Shake and Spill, Stages 3–5
Compare, Stage 1
Number Puzzles, Stages 1 and 2
Launch
Groups of 2
“Now you are going to choose from centers we have already learned.”
Display the center choices in the student book.
“Think about what you would like to do.”
30 seconds: quiet think time
Activity
Invite students to work at the center of their choice.
10 minutes: center work time
Student Facing
Choose a center.
Shake and Spill
[IMG]
Compare
[IMG]
Number Puzzles
[IMG]
Activity Synthesis
Display nine red counters and cover five yellow counters with a cup.
“We are playing with 14 counters. How many yellow counters are under the cup? How do you know?”


aligns: no