题目内容
脱式计算,能简算的要简算.
70.8-7.25-1.75
5.81+8.3+4.19+11.7
0.05×0.4×20×1.7
4.87×2.34+4.87×7.66.
70.8-7.25-1.75
5.81+8.3+4.19+11.7
0.05×0.4×20×1.7
4.87×2.34+4.87×7.66.
(1)70.8-7.25-1.75
=70.8-(7.25+1.75),
=70.8-9,
=61.8;
(2)5.81+8.3+4.19+11.7
=(5.81+4.19)+(8.3+1.7),
=10+10,
=20;
(3)0.05×0.4×20×1.7
=0.02×20×1.7,
=0.4×1.7,
=0.68;
(4)4.87×2.34+4.87×7.66
=(2.34+7.66)×4.87,
=10×4.87,
=48.7.
=70.8-(7.25+1.75),
=70.8-9,
=61.8;
(2)5.81+8.3+4.19+11.7
=(5.81+4.19)+(8.3+1.7),
=10+10,
=20;
(3)0.05×0.4×20×1.7
=0.02×20×1.7,
=0.4×1.7,
=0.68;
(4)4.87×2.34+4.87×7.66
=(2.34+7.66)×4.87,
=10×4.87,
=48.7.
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