题目

计算下面各题,能简算的要简算。 ① + + = ② + - = ③ + + - = ④ - - = ⑤ -( - )= ⑥ +( - )= 答案:① 38 + 14 + 138 = 38 + 138 + 14 =2+ 14 =2 14 ② 45 + 710 - 1120 = 1510 - 1120 = 1920 ③ 1119 + 718 + 819 - 718 =( 1119 + 819 )+( 718 - 718 )=1+0=1 ④ 32 - 1217 - 517 = 32 -( 1217 + 517 )= 32 -1= 12 ⑤ 78 -( 37 - 114 )= 78 - 514 = 2956 ⑥ 56 +( 13 - 14 )= 56 + 112 = 1112
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