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


Standard options: 
A. Prove the Pythagorean identity sin^(2)(θ) + cos^(2)(θ) = 1 and use it to find sin(θ), cos(θ),or tan(θ) given sin(θ), cos(θ), or tan(θ) and the quadrant of the angle.
B. Prove the addition and subtraction formulas for sine, cosine, and tangent and use them to solve problems.


Your response:
Thought: 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. Solving this problem does not require use of the Pythagorean identity.
Answer: B

Now, assign the following problem or activity to one or more relevant standards it aligns with.
shot_info: fl_problem_001894

HS
options: Fluently multiply multi-digit whole numbers using the standard algorithm.

Find whole-number quotients of whole numbers with up to four-digit dividends and two-digit divisors, using strategies based on place value, the properties of operations, and/or the relationship between multiplication and division. Illustrate and explain the calculation by using equations, rectangular arrays, and/or area models.

Add, subtract, multiply, and divide decimals to hundredths, using concrete models or drawings and strategies based on place value, properties of operations, and/or the relationship between addition and subtraction; relate the strategy to a written method and explain the reasoning used.
problem_activity: Narrative
The purpose of this activity is for students to find quotients of a whole number by tenths or hundredths. This activity focuses on divisors of 0.2 and 0.02 to build on students' previous work dividing by 0.1 and 0.01. The strategies, diagrams and place value reasoning used in the previous lessons still apply. Students may also think about the problems using multiplication. For example
\(1 \div 0.2 = 5\)
because
\(5 \times 0.2 = 1\)
.
Required Materials
Materials to Copy
Small Grids
Launch
Groups of 2
Give students access to blackline masters with grids.
Activity
1–2 minutes: quiet think time
8–10 minutes: partner work time
Monitor for students who represent their reasoning with:
diagrams
expressions or words using multiplication
Student Facing
Find the value of each expression. Explain or show your reasoning.
\(1 \div 0.2\)
\(2 \div 0.2\)
\(3 \div 0.2\)
\(4 \div 0.2\)
Find the value of each expression. Explain or show your reasoning.
\(1 \div 0.02\)
\(2 \div 0.02\)
\(3 \div 0.02\)
\(4 \div 0.02\)
What patterns do you notice?
Student Response
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Advancing Student Thinking
If a student is not able to use the value of the first expression in each set to find the value of the later expressions, ask them to describe what they notice and wonder about each set of expressions. Use numbers and symbols when possible to record the relationships they describe.
Activity Synthesis
Ask selected students to share the representations listed above.
“How are the representations the same? How are they different?” (They both figured out how many tenths or hundredths are in one whole. Then they multiplied that by the number of wholes. One of them used a picture and one of them reasoned about the size of tenths and hundredths to find how many 0.2's and 0.02's are in one whole.)
Display a student's completed work showing the values of the quotients.
“What patterns do you see across the sets of equations?” (The quotients with a divisor of 0.01 are 10 times larger than those with a divisor of 0.1. The quotients with a divisor of 0.1 are a tenth of the value of those with a divisor of 0.01.)
Record the patterns as students describe them.


correct_option_index: 2