few_shots: 
Example:
Concept/skill: 
Compare two decimals to hundredths by reasoning about their size. Recognize that comparisons are valid only when the two decimals refer to the same whole. Record the results of comparisons with the symbols >, =, or <, and justify the conclusions, e.g., by using a visual model.
Grade 4 expectations in this domain are limited to fractions with denominators 2, 3, 4, 5, 6, 8, 10, 12, and 100.

Problem/activity:
Task
Cruz and Erica were both getting ready for soccer.
Cruz ran 1 lap around the school.
Erica ran 3 laps around the playground.
Erica said,
I ran more laps, so I ran farther.
Cruz said,
4 laps around the school is 1 mile, but it takes 12 laps around the playground to go 1 mile. My laps are much longer, so I ran farther.
Who is right? Draw a picture to help you explain your answer.


Answer: 
No. This task does not involve comparing decimals to hundredths. Instead, it involves fraction comparisons.

Now, assess whether the following problem or activity is 'aligned' with the given Common Core standard in Mathematics.

shot_info: im_task_000212_neg_0

4
standard_description: Find the conjugate of a complex number; use conjugates to find moduli and quotients of complex numbers.
problem_activity: Warm-up
The purpose of this activity is to focus students' attention on the two parts of a complex number: the real part and the imaginary part. This will be useful in the Information Gap, when students will need to be specific about the information they want and to strategize about how to use it (MP1).
Launch
Display the following for all to see:
\((a+bi)-(\underline{\phantom{00}} + \underline{\phantom{00}}i) = \text?\)
Ask, "In order for the result of this subtraction to be a real number, what has to be true about the missing imaginary part of the complex number subtracted from
\(a+bi\)
?" (It has to match the imaginary part of the other expression so it will sum to 0, which means that
\(b\)
must go in the blank.) After quiet think time, invite students to share their thoughts with a partner. Then invite partners to share with the class.
Student Facing
Here are some complex numbers with an unknown difference:
\((10+4i)-(\underline{\phantom{00}} + \underline{\phantom{00}}i) = \text?\)
If the result of this subtraction is a real number, what could the second complex number be?
If the result of this subtraction is an imaginary number, what could the second complex number be?
Student Response
Teachers with a valid work email address can
click here to register or sign in
for free access to Student Response.
Activity Synthesis
Ask students to share the expressions they made by filling in the blanks. Highlight what is common about the responses to each question (all responses to the first question have the same imaginary part, and all responses to the second question have the same real part).
Tell students that in the next activity they will continue to reason about the real and imaginary parts of complex numbers based on what they know about how the numbers are combined.


aligns: no