few_shots: 
Example 1:
Concept/skill: 
Represent addition and subtraction with objects, fingers, mental images, drawings (Drawings need not show details, but should show the mathematics in the problem. (This applies wherever drawings are mentioned in the Standards.)), sounds (e.g., claps), acting out situations, verbal explanations, expressions, or equations.

Problem/activity:
Task
Materials
One 10-frame per pair of students (see example below)
[IMG]
Counters, 10 per pair of students
Decks of number cards 0-5 (with 4 of each number) or two 0-5 dice
Setup
This activity is done in pairs. The students sit side by side with 10-frame and deck of cards or dice. If they have cards, the cards are shuffled and placed face down in front of them.
Action
Player 1 flips a card or rolls the die. They place that many counters on the 10-frame. Player 2 flips a card or rolls the die. They place that many more counters on the 10-frame next to the counters already on the ten frame. The students count the total together.
A recording sheet can be added when the students have been introduced to equations and number sentences. For those students who can handle higher numbers, a deck of 0-10 cards and two 10-frames can be used.
This game can also be played alone.


Answer: 
Yes. This task involves representing addition with objects such as number cards and dice.

Example 2:
Concept/skill: 
Apply and extend previous understandings of multiplication and division and of fractions to multiply and divide rational numbers.

Problem/activity:
For each pair of numbers, determine if the values are equivalent. Explain your reasoning for each one.
a.
$$-0.25$$
and
$$\frac{1}{-4}$$
b.
$$-\left ( \frac{1}{4} \right )$$
and
$$\frac{-1}{-4}$$
c.
$$\frac{-1}{4}$$
and
$$-\frac{1}{4}$$


Answer: 
Yes. This problem involves understanding fractions and division to divide rational numbers, such as 1, -4, 4, and -1. This problem also involves an understanding of multiplication: if p and q are integers, then -(p/q) = (-p)/q = p/(-q).

Example 3:
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: im_task_001477_pos_0

K

fl_problem_001097_pos_0

7

fl_problem_001894_pos_0

HS_0
standard_description: Use data from a random sample to draw inferences about a population with an unknown characteristic of interest. Generate multiple samples (or simulated samples) of the same size to gauge the variation in estimates or predictions. For example, estimate the mean word length in a book by randomly sampling words from the book; predict the winner of a school election based on randomly sampled survey data. Gauge how far off the estimate or prediction might be.
problem_activity: Activity
This activity prompts students to create expressions to represent the quantities and relationships in a situation and engages them in mathematical modeling.
Students plan a pizza party and present a cost estimate. To do so, they need to consider relevant variables, make assumptions and estimates, perform calculations, and adjust their thinking along the way (MP4). Some students may choose to perform research and revise their models as they gather new information. There are many possible solutions to the task.
As students discuss their ideas, monitor for those who:
find and use actual data or exact values (for example, count the number of students in the class, research the cost of a large pizza at a nearby shop, or quickly survey the class for topping preferences)
estimate quantities based on prior knowledge (for example, the cost of a large pizza in a recent purchase, or the number of slices they and their friends generally consume at lunch time)
make assumptions about behaviors, preferences, or quantities (for instance, assume that a certain percentage of the class prefers a certain topping)
Launch
Ask students if they have ever been in charge of planning a party. Solicit a few ideas of what party planners need to consider. Ask students to imagine being in charge of a class pizza party. Explain that their job is to present a plan and a cost estimate for the party.
Arrange students in groups of 4. Provide access to calculators and, if feasible and desired, access to the internet for researching pizza prices. Students can also make estimates based on prior experience, refer to printed ads, or use their personal device to look up pricing information.
Limit the time spent on the first question to 7–8 minutes and pause the class before students move on to subsequent questions. Give groups of students 1–2 minutes to share their proposals with another group. Then, select a few groups who used contrasting strategies (such as those outlined in the Narrative) to briefly share their plans with the class. Record or display their plans for all to see.
Next, ask students to complete the remaining questions. If needed, give an example of an expression that can be written to represent a cost calculation.
Student Facing
Imagine your class is having a pizza party.
Work with your group to plan what to order and to estimate what the party would cost.
[IMG]
Record your group’s plan and cost estimate. What would it take to convince the class to go with your group’s plan? Be prepared to explain your reasoning.
Write down one or more expressions that show how your group’s cost estimate was calculated.
In your expression(s), are there quantities that might change on the day of the party? Which ones?
Rewrite your expression(s), replacing the quantities that might change with letters. Be sure to specify what the letters represent.
Student Response
Teachers with a valid work email address can
click here to register or sign in
for free access to Student Response.
Student Facing
Are you ready for more?
Find a pizza place near you and ask about the diameter and cost of at least two sizes of pizza. Compare the cost per square inch of the sizes.
Student Response
Teachers with a valid work email address can
click here to register or sign in
for free access to Extension Student Response.
Anticipated Misconceptions
If students do not understand what is meant by “quantities that might change,” ask them if it is more likely that the cost of a pepperoni pizza increases on the day of the party, or that some students are absent that day. In a model that incorporates both of these quantities, they may wish to use a number for the cost of each type of pizza and a letter for the number of students present that day.
Activity Synthesis
Invite groups who did not previously share their plans to share the expressions they wrote and explain what the expressions represent. After each group shares, ask if others calculated the costs the same way but wrote different expressions.
As students present their expressions, record the quantities that they mention and display them for all to see. Some examples:
the number of students in the class
the number of pizza slices per person
the cost of delivery
the price per topping
Briefly discuss the quantities that students anticipate would change (and therefore would replace with letters).
Explain to students that the expressions they have written are examples of mathematical
models
. They are mathematical representations of a situation in life that can be used to make sense of problems and solve them. We will look more closely at how expressions could represent the quantities in a situation like party planning, which involves certain conditions or requirements.
Representing, Conversing: MLR7 Compare and Connect.
As students share their plans with the class, call students’ attention to the different ways the quantities are represented in expressions, and to the different expressions that represent the same quantity. Take a close look at the contrasting strategies used within the context of the situation. Wherever possible, amplify student words and actions that students use to revise their models by estimating quantities and making assumptions about the situation.
Design Principle(s): Maximize meta-awareness; Support sense-making


aligns: no