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: 
Solve quadratic equations in one variable.

Answer: 
Yes. This task shows one quadratic equation with 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, does the following problem or activity enable students to learn the full intent of the following concept or skill?

shot_info: fl_problem_001894_pos_0

HS_0

im_task_000870_pos_0

HS_1

im_task_001160_pos_0

HS_2
standard_description: Use multiplication and division within 100 to solve word problems in situations involving equal groups, arrays, and measurement quantities, e.g., by using drawings and equations with a symbol for the unknown number to represent the problem.
problem_activity: Problem 1
Act 1: Watch the video
The Orange (Act-1)
.
a.   What do you notice? What do you wonder?
b.   How many linking cubes will it take to even out the balance scale? Make an estimate.
Problem 2
Act 2: Use the following information to determine how many cubes it will take until the balance is level with the orange -
[IMG]
[IMG]
Problem 3
Act 3: Watch
The Orange (Act-3)
. Was your answer reasonable? Why or why not?
Problem 4
Act 4 (the sequel):
a.   Jessica puts 28 grams of pinto beans and 36 grams of rice into a pot to make rice and beans. What is the total mass of the rice and beans?
b.   Lindsey bought 845 grams of potatoes at the grocery store. She uses some of them to make mashed potatoes. She now has 392 grams of potatoes left. How many grams of potatoes did Lindsey use to make the mashed potatoes?
c.   Jerry buys 6 bags of groceries. Each bag has a mass of 4 kilograms. What is the total mass, in kilograms, of Jerry’s grocery bags?


aligns: no