考點(diǎn):運(yùn)算定律與簡(jiǎn)便運(yùn)算
專題:運(yùn)算定律及簡(jiǎn)算
分析:(1)(3)(6)按從左到右的順序計(jì)算即可.
(2)可根據(jù)一個(gè)數(shù)減兩個(gè)數(shù)的差,等于用這個(gè)數(shù)減去兩個(gè)數(shù)的被減數(shù),加上減數(shù)的減法性質(zhì)計(jì)算.
(4)(6)根據(jù)加法交換律及結(jié)合律計(jì)算.
(5)可根據(jù)一個(gè)數(shù)減兩個(gè)數(shù),等于用這個(gè)數(shù)減去這兩個(gè)數(shù)的和的減法性質(zhì)計(jì)算.
解答:
解:(1)15+56+23
=71+23
=94;
(2)718-(518-19 )
=718-518+19
=200+19
=219;
(3)524+14+23
=538+23
=561;
(4)34+49+14+29
=34+14+(49+29)
=48+78
=126;
(5)2-27-37
=2-(27+37)
=2-64
=-62;
(6)38+27+18+57
=38+18+(27+57)
=56+84
=140
點(diǎn)評(píng):完成本題要注意分析式中數(shù)據(jù)的特點(diǎn),然后運(yùn)用合適的方法計(jì)算.