Question

口算．

0.6×0.6=	0.7×0.6=	0.8×0.6=	0.9×0.6=
0.6×0.7=	0.7×0.7=	0.8×0.7=	0.9×0.7=
0.6×0.8=	0.7×0.8=	0.8×0.8=	0.9×0.8=
0.6×0.9=	0.7×0.9=	0.8×0.9=	0.9×0.9=

Answer 1

分析：先根據6，7，8，9的乘法口訣進行計算，根據乘數的小數的位數確定積的小數的位數即可．

解答：解：

0.6×0.6=0.36	0.7×0.6=0.42	0.8×0.6=0.48	0.9×0.6=0.54
0.6×0.7=0.42	0.7×0.7=0.49	0.8×0.7=0.56	0.9×0.7=0.63
0.6×0.8=0.48	0.7×0.8=0.56	0.8×0.8=0.64	0.9×0.8=0.72
0.6×0.9=0.54	0.7×0.9=0.63	0.8×0.9=0.72	0.9×0.9=0.81

點評：本題考查了簡單的小數乘法計算，關鍵弄清積的小數部分的位數．