Question

1．口算：

1-0.38=	2.5+3.6=	1-0.01=	1.2-0.12=	3.6+4.04=
6.1-0.72=	3-1.3=	7.2-1.9=	2.4+1.9=	0.42-0.39=

Answer 1

分析 根據(jù)小數(shù)的加減乘除法的計(jì)算法則進(jìn)行口算，注意小數(shù)點(diǎn)位置．

解答

解： 1-0.38=0.62	2.5+3.6=6.1	1-0.01=0.99	1.2-0.12=1.08	3.6+4.04=7.64
6.1-0.72=5.38	3-1.3=1.7	7.2-1.9=5.3	2.4+1.9=4.3	0.42-0.39=0.03

點(diǎn)評 注意小數(shù)的加減小數(shù)點(diǎn)要對齊，小數(shù)點(diǎn)乘除注意計(jì)算結(jié)果中小數(shù)的位數(shù)．