1.填空题 (16)20=45=24÷(30)=(0.8)(填小数) 2.简便计算易错题 1613-(38-313)-58 =1613-38+313-58 =1613+313-38-58 =1913-(38+58) =1913-1 =613 0.125+811+(78-711) =18+811+78-711 =(18+78)+(811-711) =1+111 =1111 27-15+57-45 =(27+57)-15-45 =1-(15+45) =1-1 =0 613-0.6+713+0.4 =(613+713)-0.6+0.4 =1-0.6+0.4 (不用简算) =0.4+0.4 =0.8
