笔算下列各题,并验算. 801﹣564= 605﹣319= 75+508= 258+389=
= = == = == = =
看“分数墙”列式计算
口算= +8+= ﹣+=+= 3﹣﹣= 3﹣+=+= 1﹣﹣= 1++=
脱式计算,能简算要简算﹣(+)+++﹣(﹣)﹣+﹣+﹣+(+)