few_shots: 
Example 1:
Concept/skill: 
Use ratio and rate reasoning to solve real-world and mathematical problems, e.g., by reasoning about tables of equivalent ratios, tape diagrams, double number line diagrams, or equations.

Problem/activity:
You’re mixing ingredients for cookies. The recipe says to combine 6 tablespoons, or ¾ stick, of butter with 1 cup of sugar. You accidentally mix in a whole stick of butter (8 tablespoons) with the cup of sugar. How can you fix this?


Answer: 
Yes. This problem solves a real-world problem involving mixing ingredients for cookies. A student doing this problem would need to reason about equivalent ratios of butter amounts to sugar amounts.

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 that, given a system of two equations in two variables, replacing one equation by the sum of that equation and a multiple of the other produces a system with the same solutions.

Problem/activity:
Problem 1
The table below contains single equations in a single variable, single equations in two variables, and pairs of simultaneous equations in two variables. Check the appropriate box to show whether there is no solution, exactly 1 solution, or if there is an infinite number of solutions.
|                                                          | **           No solution          ** | **           Exactly 1 solution          ** | **           Infinite number of solutions          ** |
|----------------------------------------------------------|--------------------------------------|---------------------------------------------|-------------------------------------------------------|
|                       $${9=4x+7}$$                       |                                      |                                             |                                                       |
|                       $${y=3y+5}$$                       |                                      |                                             |                                                       |
|                    $${y={x\over2}}$$                     |                                      |                                             |                                                       |
|                     $${3x+6y-9=0}$$                      |                                      |                                             |                                                       |
|    $${x=y}$$                        $${1.25x=1.25y}$$    |                                      |                                             |                                                       |
| $${9.9=6x+8y}$$                        $${9x=2.5y-8.8}$$ |                                      |                                             |                                                       |
| $${11x-2y=1.5}$$                        $${11x-2y=2.5}$$ |                                      |                                             |                                                       |
Problem 2
Kim has a small container and a large container as shown.
[IMG]
It takes 16 of the small containers to fill the large container. Three small containers leave 1.95 gallons of space in the big container.
What is the size of each of the two containers?


Answer: 
No. Completing neither of these problems requires replacing one equation by the sum of that equation and a multiple of the other 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_000972_pos_0

6

fl_problem_001097_pos_0

7

fl_problem_001392_neg_0

8
standard_description: Subtract multiples of 10 in the range 10-90 from multiples of 10 in the range 10-90 (positive or zero differences), 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
In this activity, students approach 10,000 by counting up in different ways. Each count ends by reaching 10,000. Students count by different amounts and describe patterns and relationships between numbers. The activity is designed to highlight familiar counting patterns as a way to support naming and writing multi-digit numbers. The final questions in the task ask students to consider the magnitude of each number in relation to 10,000.
When students count by large numbers and examine the counted numbers, they observe patterns in how the different digits in the numbers change (MP7).
Representation: Access for Perception.
Provide access to a variety of tools that students may use to approach the task. These might include: a class set of base-ten blocks, colored pencils to color-code place values or highlight the digit that changes, and a visual display reminding students of sketches they can make to represent numbers with thousands and ten-thousands.
Supports accessibility for: Conceptual Processing, Visual-Spatial Processing, Attention
Launch
Groups of 2
“Read the directions for problem 1 and share your understanding of the directions with a partner.”
“What questions do you have before we begin?”
Activity
5 minutes: independent work time
10 minutes: partner work time
As students work,
listen for how students say the numbers and support them in using place value understanding to say the numbers correctly.
look for use of extra digits when writing numbers (for example, students write 90,500 instead of 9,500) and support students with making the revisions by having them say the numbers.
Student Facing
Record each count in the given spaces. The first number has been recorded for you.
Count by 1,000
5,000 , _____________, _____________, _____________, _____________, _____________
Count by 100
9,500 , _____________, _____________, _____________, _____________, _____________
Count by 10
9,950 , _____________, _____________, _____________, _____________, _____________
Count by 1
9,995, _____________, _____________, _____________, _____________, _____________
Complete each statement:
Ten-thousand is 1 more than _____________.
Ten-thousand is 1,000 more than _____________.
Ten-thousand is 10 more than _____________.
Ten-thousand is 100 more than _____________.
Student Response
Teachers with a valid work email address can
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for free access to Student Response.
Advancing Student Thinking
If students interpret the part a of the last problem to mean “name a number that is 10,000 more than 1,” consider clarifying by asking: “The number 10 is 1 more than what number?” and “The number 100 is 1 more than what number?” Then, restate the sentence in part a: “Ten-thousand is 1 more than what number?”
Activity Synthesis
“How is counting by 100 and 1,000 like counting by 1 and 10?” (When counting by thousands, only the thousands change. This is also the case when counting by ones, tens, and hundreds.)
Have students share their answers for the last problem.
Consider asking: “Who can restate what _____ shared?”
If needed, discuss the placement of the comma in each number.


aligns: no