问题 解答题

简算.

(1)2.4×0.19+0.24×8.1

(2)18.8×10.1-1.88

(3)0.79×0.46+7.9×0.053+0.0079.

答案

(1)2.4×0.19+0.24×8.1,

=2.4×0.19+2.4×0.81,

=2.4×(0.19+0.81),

=2.4×1,

=2.4;

(2)18.8×10.1-1.88,

=1.88×101-1.88,

=1.88×101-1.88,

=1.88×(101-1),

=1.88×100,

=188;

(3)0.79×0.46+7.9×0.053+0.0079,

=0.0079×46+0.0079×53+0.0079,

=0.0079×(46+53+1),

=0.0079×100,

=0.79.

选择题
单项选择题