问题 解答题

用简便方法计算.

(1)2.3×7.6+2.3×12.4

(2)1.25×3.2

(3)8.3×0.125×8

(4)5.9×101-5.9

(5)1.35+0.89+2.11

(6)5.12-3.43+2.88.

答案

(1)2.3×7.6+2.3×12.4,

=2.3×(7.6+12.4),

=2.3×20,

=46;

(2)1.25×3.2,

=1.25×8×0.4,

=(1.25×8)×0.4,

=10×0.4,

=4;

(3)8.3×0.125×8,

=8.3×(0.125×8),

=8.3×1,

=8.3;

(4)5.9×101-5.9,

=5.9×(101-1),

=5.9×100,

=590;

(5)1.35+0.89+2.11,

=1.35+(0.89+2.11),

=1.35+3,

=4.35;

(6)5.12-3.43+2.88,

=(5.12+2.88)-3.43,

=8-3.43,

=4.57.

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