Q2 - MATH8 (CER PRACTICE)

Do you think this problem solution is wrong?

If yes, identify which part of the solution is incorrect.

• From the representation part down to the Conclusion part. x must be the total cost of the coffee and y must be the number of extra espresso shots.

• The equation part, y = 50x + 5 down to the conclusion part.

• The solution part and the conclusion part only.

• The conclusion part only.

• I don't see any error at all.

Answer explanation

Tags

CCSS.8.EE.C.8C

Write the correct equation (in slope-intercept form) of the problem.

Let y be the total cost of the coffee. 

Let x be the number of extra espresso shots.

Tags

CCSS.6.EE.C.9

Complete the correct problem solution.

Substituting x=3 into the corrected equation (y=5x+50):

y=__+_(_)

=50+15

=65

Tags

CCSS.HSF.IF.A.2

If you have this Claim and Evidence in your C-E-R solution, How will you write your Reason?

Please write why you use such a way/method to solve each problem and explain how the claim and evidence are connected.

Answer explanation

SAMPLE REASONING:

The error in the original solution stemmed from an incorrect setup of the equation. The original equation, y=50x+5, implies that the base price is dependent on the number of shots, which misrepresents the problem’s conditions. By using the corrected equation y=50+5x, we accurately separate the fixed base cost from the variable additional cost per shot.

This correction demonstrates the importance of understanding the structure of linear equations, where a fixed cost (₱50) should be added, not multiplied, when extra variable costs (₱5 per shot) are involved. This revised approach ensures that the total cost calculation aligns with the problem’s requirements, resulting in the correct answer of ₱65 for a coffee with 3 extra espresso shots.

If you have this Claim and Evidence in your C-E-R solution, How will you write your Reason?

Please write why you use such a way/method to solve each problem and explain how the claim and evidence are connected.

Answer explanation

Sample answer:

To determine Marie's weekly pay, I used a linear equation where the total weekly pay, y, depends on the number of hours worked, x. The relationship is linear because her pay increases at a constant rate of ₱60 per hour plus a fixed ₱500 weekly. By substituting 45 hours for x, I calculated y as ₱3,200. This method aligns with solving a linear equation in two variables, where substitution allows us to find the total pay for a specified number of hours worked.

If you have this Claim and Evidence in your C-E-R solution, How will you write your Reason?

Please write why you use such a way/method to solve each problem and explain how the claim and evidence are connected.

Answer explanation

Sample REASONING:

This problem involves a relationship between the followers gained over two weeks, expressed by two equations. The number of followers last week depends on the followers gained the previous week, creating a system of linear equations. By solving this system using substitution, I determined the values of x and y that satisfy both conditions in the problem. Solving systems of linear equations allows us to handle situations where two conditions must be met, providing a reliable method to find exact values in scenarios like these.

Tags

CCSS.8.EE.C.8C

If you have this Claim and Evidence in your C-E-R solution, How will you write your Reason?

Please write why you use such a way/method to solve each problem and explain how the claim and evidence are connected.

Answer explanation

Sample REASONING:

To determine the number of small and large trees, I set up a system of linear equations based on the total number of trees and the relationship between the two types. The total tree count and the relationship that small trees are twice the number of large trees allowed me to construct two equations. By substituting one equation into the other, I solved for the exact values of x and y, which represent the quantities of large and small trees, respectively. This approach aligns with solving systems of linear equations, a reliable method for finding specific values when two conditions must be met simultaneously.

Tags

CCSS.HSA.CED.A.3

What is the purpose of the "Claim" in the C-E-R framework when solving a math problem?

• a) To list all known variables in the problem

• b) To give the final answer to the question and state the math concept used

• c) To summarize each step in the solution process

• d) To compare different ways of solving the problem

In the C-E-R method, which part should include a clear and complete solution with calculations to support the claim?

• Claim

• Evidence

• Reasoning

• Conclusion

When completing the "Reasoning" part of a C-E-R response, which of the following should you include?

• a) A detailed list of steps taken to solve the problem

• b) A restatement of the claim using different words

• c) An explanation of how the solution process supports the answer

• d) A summary of alternative methods that could be used