few_shots: 
Example 1:
Problem/activity:
Find the general solution for:
$${\mathrm{cos}\left({\pi\over2}+x\right)=\mathrm{tan}{\pi\over4}}$$


Concept/skill: 
Understand that by similarity, side ratios in right triangles are properties of the angles in the triangle, leading to definitions of trigonometric ratios for acute angles.

Answer: 
No. This problem does not directly teach how side ratios in right triangles lead to definitions of trigonometric ratios. Instead, it involves solving a trigonometric function.

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 problem or activity shown below enable students to learn the full intent of the following concept or skill?

shot_info: fl_problem_001894_neg_0

HS_0

im_task_000870_pos_0

HS_1

im_task_001160_pos_0

HS_2
standard_description: For any number from 1 to 9, find the number that makes 10 when added to the given number, e.g., by using objects or drawings, and record the answer with a drawing or equation.
problem_activity: Narrative
The goal of this activity is for students to examine different ways to write the product of a three-digit number and a two-digit number as a sum of partial products. Students match sets of partial products which can be put together to make the full product. Students are provided blank diagrams, familiar from the previous lesson, that they may choose to use to support their reasoning. In the activity synthesis, students relate the expressions and diagrams to equations to prepare them to analyze symbolic notation for partial products in the next activity.
When students relate partial products and diagrams to the product
\(245 \times 35\)
they look for and identify structure (MP7).
MLR8 Discussion Supports.
Display the following sentence frame to support small-group discussion: “I noticed _____ , so I matched . . . .” Encourage students to challenge each other when they disagree.
Advances: Speaking, Conversing
Required Materials
Materials to Copy
Partial Product Expressions
Required Preparation
Create a set of cards from the blackline master for each group of 2.
Launch
Groups of 2
Display first image from student book.
“What product does this rectangle represent?” (
\(245 \times 35\)
)
“Today, you are going to take turns with your partner picking expressions that can be added together to give the product
\(245 \times 35\)
. You can use the diagrams to explain your reasoning, if they are helpful.”
Activity
10 minutes: partner work time
Monitor for students who:
use the diagram to determine which expressions they will use.
look at the expressions and think about how they could be used to find the full product.
compute the full product in different ways.
Student Facing
[IMG]
[IMG]
[IMG]
Take turns picking out a set of expressions that are equal to
\(245 \times 35\)
when added together. Use the diagrams if they are helpful.
Explain how you know the sum of your expressions is equal to
\(245 \times 35\)
.
What is the value of
\(245 \times 35\)
? Explain or show your reasoning.
Student Response
Teachers with a valid work email address can
click here to register or sign in
for free access to Student Response.
Advancing Student Thinking
If students do not choose correct expressions to represent a sum that is equal to
\(245 \times 35\)
, refer to one of the empty boxes in the diagram and ask, “Which multiplication expression represents this partial product?”
Activity Synthesis
Invite previously selected students to share their strategies. As students share, record their reasoning with equations.
Display:
\(245 \times 30 + 245 \times 5  = 245 \times 35\)
“How do you know this equation is true?” (I can put the 30 and 5 together since they are both multiplied by 245. I see that
\(245 \times 30\)
is the top part of the diagram and
\(245 \times 5\)
is the bottom part. Together that’s the whole diagram.)


aligns: no