笔算加法(连续进位),5,湖光小学一、二年级同学给山区小朋友捐图书。,298405(),一年级捐了298本。,二年级捐了405本。,两个年级一共捐了多少本?,5,298405(),298,+405,百十个,3,0,7,5,298405(),298,+405,百十个,3,0,7,405,+298,3,0,7,答:两个年级一共捐了本。,703,703,本,用竖式计算954383,并验算。,954,+383,7,3,3,1,383,+954,7,3,3,1,验算:,1.,436,+571,7,0,0,623,+948,1,7,5,1,79,+662,1,4,7,1,先找出错在哪里,再改正过来。,2.,65,+243,8,0,2,634,+569,3,0,1,76,+646,2,1,7,1,3,2,1,2,1,2,3.用竖式计算,并验算。,53589,238907,90910,647353,=624,=1145,=1000,=1000,90,+910,0,0,0,647,+353,0,0,0,1,238,+907,5,4,1,535,+89,4,2,6,910,+