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用递等式计算,能简算的要简算

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用递等式计算,能简算的要简算
(8.4+16.35)+4.65          
24.73-8.92+5.37-11.0812.7+[18.4+(19.74-9.34)]
(125×99+125)×645600÷(28÷4)(13.1-9.28)-(4.5-2.74)
 23.404-(1.47+10.56)78×4×2×125
用递等式计算,能简算的要简算
(1)(8.4+16.35)+4.65
=8.4+(16.35+4.65)
=8.4+21
=29.4;
(2)24.73-8.92+5.37-11.08
=(24.73+5.37)-(8.92+11.08)
=30.1-20
=10.1;
(3)12.7+[18.4+(19.74-9.34)]
=12.7+[18.4+10.4]
=12.7+28.8
=41.5;
(4)(125×99+125)×64
=125×(99+1)×64
=125×100×64
=12500×64
=800000;
(5)5600÷(28÷4)
=5600÷7
=800;
(6)(13.1-9.28)-(4.5-2.74)
=3.82-1.76
=2.06;
(7)23.404-(1.47+10.56)
=23.404-12.03
=11.374;
(8)78×4×2×125
=78×(4×2×125)
=78×(8×125)
=78×1000
=78000.