Data are reported for the classroom observational portion of a cross-sectional study conducted in Tasmania, Australia to examine the acquisition and development of addition and subtraction skills in young children. During the study, a group of students in grades l, 2, and 3 who differed in cognitive processing skills were observed during mathematics instruction. Frequencies of teacher and pupil behaviors observed in each of five classrooms during a period of three months in l980 are reported, as well as a brief discussion of results. From these data, it can be concluded that variations in allocated time are due not to differences in cognitive level of children but to difference in the actions of teachers, school policy and procedures, or grade level of instruction. (MNS)