I will say what we did work thru some multiplication of integers as repeated addition and scaling, just to show that the answers "come out the same". I used the scaling by a fraction to show that the repeated addition method doesn't work on all classes of numbers. (We've talked some about the difference between integers and real numbers.)
The gist of my statement was something like: Adding repeatedly is a fine method to solve this kind of problem but it doesn't for all classes of numbers. We can't say, like we can w/ addition and subtraction, that multiplication implies a specific direction of movement (towards or away from zero) on the number line.
I wasn't really trying to analyze your approach, more speculating that getting in front of the teacher probably doesn't matter. It's the insight that multiplication isn't strictly equivalent to addition that matters, and illustrating that they are often equivalent probably doesn't block that insight.
The gist of my statement was something like: Adding repeatedly is a fine method to solve this kind of problem but it doesn't for all classes of numbers. We can't say, like we can w/ addition and subtraction, that multiplication implies a specific direction of movement (towards or away from zero) on the number line.