Numerous studies indicate that performance in solving single step multiplicative word problems is influenced by both problem structure and the types of numbers involved in the problem. For example, including numbers less than one often increases the difficulty of a problem. What remains unclear is how problem structure and number type interact in influencing difficulty. This study systematically investigated these two factors with math-proficient and remedial college students. Findings indicate that it is the role played by fractions in word problems that influences difficulty rather than simply the number of fractions in the problem. Pedagogical strategies for improving students' ability to perceive and represent multiplicative word problems are discussed. (Author)