1、,整理与复习,冀教版数学一年级上册第九单元,教学目标,1、经历小组合作整理、交流、讨论2 0以内退位减法表的过程。 2、能把20以内的退位减法算式整理在减法表中，能发现20以内退位减法表中的规律。 3、积极参加小组合作活动，获得小组合作解决问题的成功经验。,134,167,157,179,188,119,129,138,189,148,136,197,156,小组合作。把20以内的退位减法整理到表格中，想一想，该按什么规律整理呢？,145,146,147,148,149,156,157,158,159,167,168,169,178,179,189,112,113,114,115,116,11
2、7,118,119,123,124,125,126,127,128,129,134,135,137,138,139,136,竖,着,看,145,146,147,148,149,156,157,158,159,167,168,169,178,179,189,112,113,114,115,116,117,118,119,123,124,125,126,127,128,129,134,135,137,138,139,136,11？,12？,13？,14？,15？,16？,17？,18？,横,着,看,145,146,147,148,149,156,157,158,159,167,168,169,17
3、8,179,189,112,113,114,115,116,117,118,119,123,124,125,126,127,128,129,134,135,137,138,139,136,9,8,7,6,5,4,3,2,1.你还发现有什么规律的排列？ 2.这些题你是怎样算的？,145,146,147,148,149,156,157,158,159,167,168,169,178,179,189,112,113,114,115,116,117,118,119,123,124,125,126,127,128,129,134,135,137,138,139,136,练一练,1.用9、8、17写出两个加法算式和两个减法算式。,根据第1题，自己选择三个数，试着写出四个算式。,2.看图列式计算。,？,=,？,=,3.看谁算得又对又快。,4.提问题，并解答。,
