Read the word problem. Look at the student's work and solution. Henry and Rick have 265.3 downloaded minutes of music. If Henry has 112 minutes, how many minutes belong to Rick?

Question

INCORRECT WORK
________________
r = the number of minutes that belong to Rick.
112+r 265.3 =
-112
+112
r = 377.3
Rick has 377.3 minutes.
___________________

Part A: Identify the error in the student's work and describe it.

Answer 1

The error in the student's work is in the equation they set up to solve the problem. The student incorrectly arranged the equation as "112 + r 265.3 =", which is not a proper equation.

The correct equation should be:

112 + r = 265.3

The student did not include an equality sign in the setup of the equation, making it unclear how the relationship between Henry's and Rick's minutes was established. Moreover, the student incorrectly solved for Rick's minutes by improperly manipulating the equation. The correct manipulation would involve subtracting 112 from both sides:

r = 265.3 - 112 = 153.3

Thus, the correct amount of minutes that belong to Rick is 153.3 minutes, not 377.3 minutes.