This study explores mathematics performance between boys and girls in terms of attitude toward mathematics and the average standardized scores in reading and mathematics between the 30th and 85th percentiles. Participants were 7th grade students from a private school in an urban area who registered in a course intended for students of average ability. The reading and mathematics subtests of the Iowa Test of Basic Skills (ITBS) were used to determine relationships between the scores and confidence to predict achievement in this course. The results show that the boys' standardized test scores were higher than the girls' scores, and that achievement in this group could not be predicted by standardized scores in reading and mathematics. Both of these results are in contrast to reports by many previous research findings. (Contains 10 references.) (KHR)