怎樣簡(jiǎn)便就怎樣算.
12.75-(6.57+2.75)
4.8÷0.24÷2
5.8-1.29+4.2-7.71
0.25×1.25×32.
解:(1)12.75-(6.57+2.75)
=12.75-2.75-6.57,
=10-6.57,
=3.43;
(2)4.8÷0.24÷2
=4.8÷2÷0.24,
=2.4÷0.24,
=10;
(3)5.8-1.29+4.2-7.71
=(5.8+4.2)-(1.29+7.71),
=10-9,
=1;
(4)0.25×1.25×32
=0.25×4×(1.25×8),
=1×10,
=10.
分析:(1)可根據(jù)一個(gè)數(shù)減兩個(gè)數(shù)的和,等于用這個(gè)數(shù)分別減去這兩個(gè)數(shù)的和的減法性質(zhì)計(jì)算;
(2)可根據(jù)交換律計(jì)算;
(3)可根據(jù)加法交換律及一個(gè)數(shù)減兩個(gè)數(shù),等于減去這兩個(gè)數(shù)的和的減法性質(zhì)計(jì)算;
(4)可將32拆分為4×8后根據(jù)乘法交換律及結(jié)合律計(jì)算.
點(diǎn)評(píng):完成此類題目要注意分析式中數(shù)據(jù)的特點(diǎn),然后運(yùn)用合適的方法計(jì)算.