按规律填数. (1)9 4.5 2.25_ (2)125 50 20_ 1.28.

问题描述:

按规律填数.
(1)9     4.5    2.25______
(2)125   50   20____________    1.28.

(1)2.25÷2=1.125;
(2)20×0.4=8;
8×0.4=3.2,
故答案为:1.125,8,3.2.