【人教版】2020年春一下数学：第2单元-20以内的退位减法第2课时 练习课 9页

优翼 www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com 第 2 课时 练 习 课 20以内的退位减法 2 www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com 问题：（ 1 ）仔细观察这幅图，你都知道了什么？ （ 2 ）你能提个问题，并列式解答吗？ （ 3 ）仔细观察这两个算式，你有什么发现吗？ 1. 一图两式，揭示加减法之间的联系 （ 4 ）如果十几减 9 不会了，我们可以借助什么 来思考呢？ 9 ＋ 4 ＝ 13 13 － 9 ＝ 4 一 巩固练习 www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com 9 ＋ 5 ＝ 14 14 － 9 ＝ 5 你能提个问题，并列式解答吗？ 一 巩固练习 www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com 问题：怎么算得这么快，能说说你们是用什么方法算的吗？ ＋ 9 2 5 6 7 8 9 3 4 18 12 13 11 15 17 16 14 一 巩固练习 2. www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com 2+9= 11 6+9= 15 8+9= 17 5+9= 14 3+9= 12 7+9= 16 4+9= 13 9+9= 18 11 － 9= 2 14 － 9= 5 17 － 9= 8 12 － 9= 3 15 － 9= 6 16 － 9= 7 18 － 9= 9 13 － 9= 4 一 巩固练习 3. www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com 2 5 8 10 3 13 8 10 14 一 巩固练习 4. www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com 16 - 9 7 14 - 9 5 一 巩固练习 5. 一 巩固练习 www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com 一 巩固练习 www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com www.youyi100.com 9 个女生。