The present invention automatically replaces in an assessment response a string of mathematical symbols determined to be ambiguous with an unambiguous string of mathematical symbols. An editing tool may receive an assessment response from a client over a communication network. The assessment response may comprise i) a text with a mathematical meaning and ii) a string of mathematical symbols. The text and the string of mathematical symbols represent different non-overlapping characters in the assessment response. The editing tool may match the string of mathematical symbols with a known ambiguous string of mathematical symbols and determine the mathematical meaning in the text of the assessment response. The editing tool may replace the string of mathematical symbols determined to be ambiguous with an unambiguous string of mathematical symbols to generate an updated assessment response. The editing tool may transmit the updated assessment response to the client for display.