“望”:病例观察“乘法分配律”是苏教版教材四年级下册的内容。课一开始,教师出示如下两组题目,男女生各做一组,比一比谁算得快。教师意在通过做第一组题的女生获胜引出新授内容。第一组第二组(4+6)×2 4×2+6×2(9+11)×15 9×15+11×15(23+17)×40 23×40+17×40(45+55)×9 45×9+55×9结果,意外的是一位男生得了第一名。他在说 “Wang ”: Case observation “Multiplication Distribution Law ” is the content of the fourth grade of the textbooks of the Sujiao version. The beginning of the class, teachers produce the following two groups of subjects, boys and girls to do a group, who is faster than one count. The teacher intends to introduce a new assignment by winning the first group of girls. The first group of the second group (4 + 6) × 2 4 × 2 + 6 × 2 (9 + 11) × 15 9 × 15 + 11 × 15 (23 + 17) × 40 23 × 40 + 17 × 40 (45 +55) × 9 45 × 9 + 55 × 9 As a result, a guy unexpectedly got first place. He is saying