Some elementary students may exhibit challenging externalizing or internalizing behaviors in addition to difficulty with mathematics. In this study, we explored the behavioral patterns of 441 3rd-grade students with and without mathematics difficulty (MD). Compared to students without MD, students with MD demonstrated higher rates of externalizing and internalizing behaviors. We then randomly assigned 162 3rd-grade students with MD to receive a 10-week word-problem intervention or to be in a business-as-usual comparison group. Within the word-problem intervention, students with MD who exhibited higher occurrences of externalizing behaviors performed significantly lower on a word-problem measure than students without as many occurrences of externalizing behaviors. Response to the word-problem intervention did not differ based on internalizing behavior patterns. [This paper was published in "Remedial and Special Education" v42 n3 p182-192 2021 (EJ1295309).]