The Effect of Instruction on the Development of Strategic Arithmetic Competency in Iranian Children

60 first graders were randomly selected from primary schools in Tehran, Iran. In the pre-test stage, Form A of the Individual Differences in Children’s Addition Strategy Choices (Kerkman & Siegler, 1997) was admi- nistered to both experimental and control groups. Next, instructions of using min strategy were given to partici- pants in the experimental group, but not in the control group. In the post-test stage, Form B of the same test was administered to both groups. Findings showed that instru- ctions influenced the frequency of usage of min strategy in the experimental group. But in spite of, the two groups in retrieving the responses were not significantly different, the accuracy of backup and min strategy were greater in the experimental group than in the control group. Two groups were significantly different in the speed at which they executed the min strategy and the experimental group was faster than the control group.