Question

a student is asked to calculate the volume, in milliliters, of 2 cups of oil. there are 225mL per cup. the student calculates the volume as follows:

volume=2cups x 1cup/25mL= 8 cups
list three errors the student made

Answer 1

@jjqls51 would you have done it the same way? =)

Answer 2

yes

Answer 3

If the problem asks for mililiters... why would you give them cups?

Answer 4

How did you start with 2 cups and end up with 8 cups?

Answer 5

0.08 sorry

Answer 6

0.8 of what?

Answer 7

0.8 cups^2/mL

Answer 8

that would be the unit, right? cup time cup divided by mL

Answer 9

i really don't know

Answer 10

a conversion factor should cancel units

Answer 11

Well, the point is, if you wanna get rid of the cup, you have to divide by cup and multiply by mL

Answer 12

@EulerGroupie I'm gonna go to bed, you can take it from here if you like.

Answer 13

k

Answer 14

so, what @wio is saying is that cups needs to cancel cups in the denominator so that only mL is left on top.

Answer 15

So one problem is that the conversion factor is upside down. It should have the mL number on top, and the cup number in the denominator.

Answer 16

Another problem is that they dropped the 2 from 225mL.

Answer 17

i get it

Answer 18

The third problem is that even the numbers that they used, don't get 8.

Answer 19

Fantastic!