19.98×37-199.8×1.9+1998×0.82888+32×0.125×0.257.8÷[32×(1-)+3.6]+++…+.
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解:
(1)19.98×37-199.8×1.9+1998×0.82,
=19.98×37-19.98×19+19.98×82,
=19.98×(37-19+82),
=19.98×100,
=1998;
(2)888+32×0.125×0.25,
=888+(8×4)×0.125×0.25,
=888+(8×0.125)×(4×0.25),
=888+1×1,
=888+1,
=889;
(3)7.8÷[32×(1-)+3.6],
=7.8÷[32×+3.6],
=7.8÷[12+3.6],
=7.8÷15.6,
=0.5;
(4)+++…+,
=(1-)+(-)+(-)+…+(-),
=1-+-+-+…+-,
=1-,
=.
解析分析:(1)根据乘法分配律进行简算;(2)把32拆成8×4,然后再根据乘法交换律和结合律进行简算;(3)先算小括号里面的减法,再算中括号里面的乘法,再算中括号里面的加法,最后算除法;(4)根据分数的拆项进行简算即可.
点评:四则运算,先弄清运算顺序,然后再进一步计算,能简算的要简算.