Here is the situation:
A math teacher (me) wrote on the board:
25% of an investment is accounted for $1500. Evaluate the amount of the investment.
An observer (another math teacher) mentioned afterwards that my sentence was a problem and needed to be more "defined". I asked the person what I should have written instead. He added the word "as" to the sentence: "25% of an investment is accounted for as $1500."
Am I correct? Is he correct? Are we both correct?
Does the word "as" add anything to the sentence?