2÷[(127-136)×9]×61.25×67.875+0.125×6787.5+125×0.53375.
问题描述:
2÷[(
-1 27
)×9]×61 36
1.25×67.875+0.125×6787.5+125×0.53375.
答
(1)2÷[(
-1 27
)×9]×6,1 36
=2÷[
×9-1 27
×9]×6,1 36
=2÷[
-1 3
]×6,1 4
=2÷
×6,1 12
=2×12×6,
=144;
(2)1.25×67.875+0.125×6787.5+125×0.53375,
=125×0.67875+125×6.7875+125×0.53375,
=125×(0.67875+6.7875+0.53375),
=125×8,
=1000.
答案解析:(1)中括号内运用乘法分配律简算,然后再算括号外的除法和乘法;
(2)根据数字特点,原式变为125×0.67875+125×6.7875+125×0.53375,运用乘法分配律简算.
考试点:整数、分数、小数、百分数四则混合运算;运算定律与简便运算.
知识点:考查了运算定律与简便运算,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律简便计算.