few_shots: 
Example:
Concept/skill: 
Use addition and subtraction within 100 to solve one- and two-step word problems involving situations of adding to, taking from, putting together, taking apart, and comparing, with unknowns in all positions, e.g., by using drawings and equations with a symbol for the unknown number to represent the problem.

Problem/activity:
Stage 1: Money
 Required Preparation
 Materials to Copy
 Blackline Masters
 Would You Rather Stage 1 Spinner
 Would You Rather Stage 1 Recording Sheet
 
 Narrative
 The first partner spins to get a group of coins. They write a question that compares the amount they spun to a different group of coins that they make up.

Answer: 
No. This activity does not involve addition or subtraction, or unknowns in different positions of equations or drawings.

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

shot_info: im_center_000269_neg_0

2
standard_description: Explain how the criteria for triangle congruence (ASA, SAS, and SSS) follow from the definition of congruence in terms of rigid motions.
problem_activity: Task
In the two triangles below, angle $A$ is congruent to angle $D$, side $AC$ is congruent to side $DF$ and side $AB$ is congruent to side $DE$:
[IMG]
Sally reasons as follows: "If angle $A$ is congruent to angle $D$ then I can move point $A$ to point $D$ so that side $AB$ lies on top of side $DE$ and side $AC$ lies on top of side $DF$. Since $AB$ and $DE$ are congruent as are $AC$ and $DF$ the two triangles match up exactly and so they are congruent.''
Explain Sally's reasoning for why triangle $ABC$ is congruent to triangle $DEF$ using the language of reflections:
Construct a reflection which maps point $A$ to point $D$. Call $B'$ and $C'$ the images of $B$ and $C$ respectively under this reflection.
Construct a reflection which does not move $D$ but which sends $B'$ to $E$.  Call $C''$ the image of $C'$ under this reflection.
Construct a reflection which does not move $D$ or $E$ but which sends $C''$ to $F$.


aligns: yes