The purposes of this research were 1) to develop instructional packages on mathematics entitled “Division” for Prathom suksa 4 which contained the efficiency criterion of 75/75, 2) to compare the students’ achievements gained before and after they had learnt through the developed instructional packages on mathematics entitled “Division” for Prathom suksa 4, 3) to investigate the students’ satisfaction of the developed instructional packages on mathematics entitled “Division” for Prathom suksa 4.

The subjects were 23 Prathom suksa 4 students studying in the first semester of 2009 academic year at Ban Tungmontatwittaya School under the Office of Sakon Nakhon Educational Service Area 3. They were purposively selected. The tools used in this experiment were lesson plans, the instructional packages on mathematics entitled “Division” for Prathom suksa 4, an achievement test, and a question are to measure the students’ satisfaction of the instructional packages on mathematics entitled “Division” for Prathom suksa 4. One Group Pretest-Posttest Design was adopted for this study. The statistics used for data analysis include mean, standard deviation, percentage, and t-test (Dependent Samples).

The study revealed the following results:

1. The instructional packages on mathematics entitled “Division” for Prathom suksa 4 had their efficiency of 79.21/77.39 which was higher than the set criterion.

2. After the students had learnt through the instructional packages on mathematics entitled “Division” for Prathom suksa 4, their achievement was statistically higher than that of before at .01 level significance.

3. The students’ satisfaction of the developed instructional packages on mathematics entitled “Division” for Prathom suksa 4, was at the high level.