Fraction arithmetic facility is fundamental to learning more advanced math topics. However, attaining the ability to add and subtract fractions is hard for many students. The present longitudinal study examined students' growth on simple addition and subtraction word problems between fourth and sixth grades (N = 536). Latent class growth analyses…

Forty-six junior high students were administered six tests after a variety of instructional units using PLATO and classroom instruction. Twenty-seven procedural errors in signed-number arithmetic problems were classified into two groups to facilitate investigating error changes at different times and designing remedial instruction. (BS)