脱式计算. 24+16×11÷81.25×32×2.5(2.8+3.85÷3.5)×0.210.9-(+9.6÷4).
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解:(1)24+16×11÷8,
=24+176÷8,
=24+22,
=46;
(2)1.25×32×2.5,
=1.25×4×8×2.5,
=(1.25×8)×(2.5×4),
=10×10,
=100;
(3)(2.8+3.85÷3.5)×0.2,
=(2.8+1.1)×0.2,
=3.9×0.2,
=0.78;
(4)+-+,
=(-)+(+),
=+1,
=1;
(5)10.9-(+9.6÷4),
=10.9-(+2.4),
=10.9-2.8,
=8.1;
(6),
=÷[1-],
=÷,
=5.
解析分析:(1)先算乘法,再算除法,最后算加法;
(2)先把32分解成4×8,再运用乘法结合律简算;
(3)先算小括号里面的除法,再算小括号里面的加法,最后算括号外的乘法;
(4)根据加法结合律简算;
(5)先算小括号里面的除法,再算小括号里面的加法,最后算括号外的减法;
(6)先算小括号里面的加法,再算中括号里面的减法,最后算括号外的除法.
点评:本题考查了四则混合运算,注意运算顺序和运算法则,灵活运用所学的运算定律进行简便计算.