题目

用适当的方法计算: (1) 0.36+(-7.4)+0.5+(-0.6)+0.14; (2) (-2.125)+ +(-3.2); (3) . (4) |-0.75|+(-3)-(-0.25)+ . (5) 答案: 解:0.36+(-7.4)+0.5+(-0.6)+0.14; 原式=(0.36+0.14)+[(-7.4)+(-0.6)]+0.5 =0.5+(-8)+0.5 =-7. 解:原式=[(-2.125)+(+5 18 )]+[(+3 15 )+(-3.2)] =3. 解:原式=[(-2 35 )+(-3 25 )]+[(+3 14 )+(+2 34 )]+[(-1 12 )+(+1 13 )] =(-6)+6+(- 16 ) =- 16 . 解:原式=0.75-3+0.25+ 18 + 78 =(0.75+0.25)+( 18 + 78 )-3 =1+1-3 =-1. 解:原式=-81÷ 134 × 49 ÷ 1413 =-81× 413 × 49 × 1314 =-10 27 .
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