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: Express a fraction with denominator 10 as an equivalent fraction with denominator 100, and use this technique to add two fractions with respective denominators 10 and 100. (Students who can generate equivalent fractions can develop strategies for adding fractions with unlike denominators in general. But addition and subtraction with unlike denominators in general is not a requirement at this grade.) For example, express 3/10 as 30/100, and add 3/10 + 4/100 = 34/100.
Grade 4 expectations in this domain are limited to fractions with denominators 2, 3, 4, 5, 6, 8, 10, 12, and 100.
problem_activity: Problem 1
A dime is
$${{1\over10}}$$
of a dollar and a penny is
$${{1\over100}}$$
of a dollar.
Would you rather have 4 one-dollar bills and 1 dime, 42 dimes, or 413 pennies? Justify your answer.
Problem 2
a.   Decide whether each of these has the same value as 3.57. Explain your reasoning.
357 tenths
357 hundredths
3 ones 57 tenths
3 ones 57 hundredths
34 tenths 17 hundredths
3 ones 7 hundredths 5 tenths
b.   Find as many ways as you can to make
$$2 \frac{4}{10}$$
using ones, tenths, and hundredths. If you think you have found all the ways, explain how you know your list is complete.
Problem 3
a.   What number represents the same amount as 1 one 70 hundredths?
b.   What number represents the same amount as 40 tenths 9 hundredths?
c.   What number represents the same amount as 268 hundredths?
d.   What number represents the same amount as 2 ones 14 tenths?
e.   What number represents the same amount as 3 ones 16 tenths 25 hundredths?


aligns: yes