题目
计算下面各题,能简算的要简算
(1)
+ -
(2)
+ +
(3)
-( - )
(4)
- + -
答案: 解: 85 + 512 - 35 =85- 35+ 512 =55+512 =1512
解: 109+ 1417 + 317 =109+(1417 + 317) =109+1 =219
解: 710 -( 12 - 15 ) =710 -12+15 =710-510+210 =210+210 =410 =25
解: 511 - 38 + 611 - 38 =(511+ 611)-(38+38) =1-68 =28 =14