能简算的要简算.
①23×+57÷
②1.36×2.7+13.6×0.73
③0.25×1.25÷
④(+-)×24
⑤[1-÷(+×)]÷
⑥2008×.
网友回答
解:①23×+57÷,
=(23+57)×,
=80×,
=30;
②1.36×2.7+13.6×0.73,
=1.36×2.7+1.36×7.3
=1.36×(2.7+7.3),
=1.36×10,
=13.6;
③0.25×1.25÷,
=0.25×1.25×32,
=(0.25×4)×(1.25×8),
=1×10,
=10;
④(+-)×24,
=×24+×24-×24,
=9+21-16,
=14;
⑤[1-÷(+×)]÷,
=[1-÷1]÷,
=÷,
=;
⑥2008×,
=(2007+1)×,
=2007×+,
=1+,
=1.
解析分析:①②④⑥利用乘法分配律简算,②把13.6×0.73化成1.36×7.3,⑥题要先把2008化成(2007+1),再利用乘法分配律简算;③把÷化成×32,再把32分成4×8,然后把0.25和4结合,1.25和8结合,利用乘法结合律简算;⑤直接利用分数的四则混合运算的顺序计算解答.
点评:本题主要利用乘法分配律进行简算.注意灵活分解转化数.