few_shots: 
Example:
Concept/skill: 
Explain why a fraction a/b is equivalent to a fraction (n × a)/(n × b) by using visual fraction models, with attention to how the number and size of the parts differ even though the two fractions themselves are the same size. Use this principle to recognize and generate equivalent fractions.
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: 
Yes. This task asks students to compare two fractions that are equal. The students need to explain why the two fractions are equal by drawing a picture, which involves using visual fraction models.

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

shot_info: im_task_000212_pos_0

4
standard_description: Create equations and inequalities in one variable and use them to solve problems. Include equations arising from linear and quadratic functions, and simple rational and exponential functions.
problem_activity: Task
A government buys $x$ fighter planes at $z$ dollars each,
and $y$ tons of wheat at $w$ dollars each. It spends a total of $B$
dollars, where $B = xz + yw$. In (a)–(c), write an
equation whose solution is the given quantity.
The number of tons of wheat the government can afford to buy if it
spends a total of \$100 million, wheat costs  \$300 per ton, and it must
buy 5 fighter planes at \$15 million each.
The price of fighter planes if the government bought 3 of them, in addition to $10,\!000$ tons of wheat at \$500 a ton, for a total of \$50 million.
The price of a ton of wheat, given that a fighter plane costs $100,\!000$ times as much as a ton of wheat, and that the government bought 20 fighter planes
and $15,\!000$ tons of wheat for a total cost of
\$90 million.


aligns: yes