(1)如图1,过A点作直线l的平行线.(2)如图2,过B点作直线l的垂线.
把算式写完整. 327+915 =327+ + + = + + = + = 705﹣398 =705﹣ + = + = .
163×39﹣163×29.
699+736+101+364.
怎样简便就怎样算:××2442×(﹣)(+)××﹣×.
252+318+248+82.