Math is traditionally taught using step-by-step directions which must be followed in order to get the correct answer.
But, is it wrong to go about getting the correct answer a different way?
Some of the best math teachers are allowing less efficient approaches to achieving the correct answers from their students in order to insure that the student is understanding the underlying MEANING of the math skill. For example, when multiplying a long number, taking the time to expand each digit into its full expanded notation is a long and tedious way to get to the answer. However, it may require months of multiplying in this fashion until students discover the shortcuts for themselves. The shortcuts (carrying) may not remind the students of the actual place value for each digit.
When teaching math, multiple strategies is always a sign that the student is flexible in their mathematical thinking and that they have better comprehension of the math laws and principles than students who depend solely on rote memory of the steps.