人教版五年级上册数学作业本3小数除法用计算器探索规律答案

1、略
 
2、（1）4 × 9 = 36
44 × 99 = 4356
444 × 999 = 443556
6 × 9 = 54
66 × 99 = 6534
666 × 999 = 665334
（2）5 × 9 = 45
55 × 99 = 5445
555 × 999 = 554445
7 × 9 = 63
77 × 99 = 7623
777 × 999 = 776223
 
3、54     45.54     445.554     4445.5554     44445.55554
 
4、2.8     28
     280     0.28