(共26张PPT)
做个减法表
小学数学·一年级(上)
北师大版·第三单元
经历小组合作,整理、交流10以内减法表的过程。
能把10以内的减法算式有规律地整理在减法表中,能发现减法表中的简单规律,熟练地口算10以内的加减法。
积极参与小组合作学习,体验与同伴合作学习的快乐。
重
让学生进行自主探索、合作交流,经历研究与探索的过程。
通过小组交流,列出所有算式,对10以内的减法进行归纳,并从中发现规律。
同学们,前面我们已经运用小组合作完成了对10以内加法表的整理,大家整理得很好。今天我们就一起来整理10以内的减法表,仍然由同学们自己来进行整理,你们有信心做好吗
同学们看一看教材第51页笑笑做的减法表,你们发现这些算式的排列有什么特点吗 小组讨论一下,然后分工进行整理。
看谁算得又对又快?
8-3=
9-2=
7-1=
10-3=
8-5=
5-3=
9-0=
7-4=
10-6=
9-5=
6-2=
9-3=
4-0=
5-2=
2-1=
5
7
6
7
3
2
9
3
4
4
4
6
4
3
1
21cnjy.com
6-4
6-5
10-2
8-0
5-1
6-6
5-3
9-1
6-3
6-0
6-1
6-3
5-2
6-2
5-0
你能把10以内的减法算式写在卡片上吗?
5-4
5-5
怎么整理呢?按照什么规律整理?
找出6减几的算式排一排
6-4
6-5
10-2
8-0
5-1
6-6
5-3
9-1
6-3
6-0
6-1
5-3
5-2
6-2
5-0
5-4
5-5
6-4
6-5
10-2
8-0
5-1
6-6
5-3
9-1
6-3
6-0
6-1
6-3
5-2
6-2
5-0
5-4
5-5
把得数是8的算式找出来
6-4
6-5
10-2
8-0
5-1
6-6
5-3
9-1
6-3
6-0
6-1
6-3
5-2
6-2
5-0
5-4
5-5
找出5减几的算式排一排
10
9
8
7
6
5
4
3
2
0
1
2-2
6-6
10-10
1-0
2-1
5-4
10-9
10-8
9-7
6-4
4-2
3-1
5-3
2-0
3-0
6-3
7-4
8-5
10-6
4-0
5-1
9-3
8-2
6-0
7-1
9-0
10-1
10-0
你能完成下表吗?
9-9
8-8
7-7
5-5
4-4
3-3
1-1
0-0
9-8
8-7
7-6
6-5
4-3
3-2
8-6
7-5
10-7
9-6
9-5
8-4
10-5
9-4
8-3
7-2
6-1
5-0
10-3
9-2
8-1
7-0
10-2
9-1
5-2
4-1
7-3
6-2
10-4
8-0
竖着看,横着看,斜着看,你发现了什么规律?
10
9
8
7
6
5
4
3
2
0
1
2-2
6-6
10-10
1-0
2-1
5-4
10-9
10-8
9-7
6-4
4-2
3-1
5-3
2-0
3-0
6-3
7-4
8-5
10-6
4-0
5-1
9-3
8-2
6-0
7-1
9-0
10-1
10-0
横着看
9-9
8-8
7-7
5-5
4-4
3-3
1-1
0-0
9-8
8-7
7-6
6-5
4-3
3-2
8-6
7-5
9-6
9-5
8-4
9-4
8-3
7-2
6-1
5-0
9-2
8-1
7-0
9-1
5-2
4-1
7-3
6-2
8-0
得数递增1
被减数相同
减数递减1
10-7
10-5
10-4
10-3
10-2
21cnjy.com
10
9
8
7
6
5
4
3
2
0
1
2-2
6-6
10-10
1-0
2-1
5-4
10-9
10-8
9-7
6-4
4-2
3-1
5-3
2-0
3-0
6-3
7-4
8-5
10-6
4-0
5-1
9-3
8-2
6-0
7-1
9-0
10-1
10-0
竖着看
9-9
8-8
7-7
5-5
4-4
3-3
1-1
0-0
9-8
8-7
7-6
6-5
4-3
3-2
8-6
7-5
9-6
9-5
8-4
9-4
8-3
7-2
6-1
5-0
9-2
8-1
7-0
9-1
5-2
4-1
7-3
6-2
8-0
得数不变
被减数和减数都递减1
10-7
10-5
10-4
10-3
10-2
2-2
6-6
10-10
9-9
8-8
7-7
5-5
4-4
3-3
1-1
0-0
10
9
8
7
6
5
4
3
2
0
1
2-2
6-6
10-10
1-0
2-1
5-4
10-9
10-8
9-7
6-4
4-2
3-1
5-3
2-0
3-0
6-3
7-4
8-5
10-6
4-0
5-1
9-3
8-2
6-0
7-1
9-0
10-1
10-0
斜着看
9-9
8-8
7-7
5-5
4-4
3-3
1-1
0-0
9-8
8-7
7-6
6-5
4-3
3-2
8-6
7-5
9-6
9-5
8-4
9-4
8-3
7-2
6-1
5-0
9-2
8-1
7-0
9-1
5-2
4-1
7-3
6-2
8-0
得数递减1
被减数递减1减数不变
10-7
10-5
10-4
10-3
10-2
1-0
2-0
3-0
4-0
6-0
9-0
10-0
0-0
5-0
7-0
8-0
10
9
8
7
6
5
4
3
2
0
1
2-2
10-10
1-0
2-1
5-4
10-9
10-8
4-2
5-3
2-0
7-4
8-5
10-6
4-0
5-1
8-2
7-1
10-1
10-0
你会填了吗?
8-8
7-7
5-5
4-4
1-1
0-0
8-7
7-6
4-3
8-6
7-5
10-7
8-4
10-5
8-3
7-2
5-0
10-3
8-1
7-0
10-2
5-2
4-1
7-3
10-4
8-0
9-9
9-8
9-6
9-5
9-4
9-2
9-1
9-7
9-3
6-5
6-1
6-2
3-3
3-2
横着得数递增1
被减数相同
减数递减1
9-0
6-6
6-4
6-0
6-3
3-1
3-0
21cnjy.com
这几个算式都是6减几的。
这几个算式得数都是8。
6 – 4
6 – 3
6 – 2
6 –1
6 – 0
6 – 2
6 – 3
6 – 4
6 – 5
6 – 6
找出6减几的算式,排一排。
6–6=
6–5=
6–0=
6–1=
你能找出得数是8的减法算式吗?排一排。
8–0=
8–0=
9–1=
9–1=
10–2=
10–2=
我知道了减法表的规律,能根据减法表规律写全10以内的减法
10
9
8
7
6
5
4
3
2
0
1
2-2
10-10
10-8
4-2
5-3
2-0
7-4
8-5
8-2
7-1
10-1
10-0
这样会填吗?
8-8
7-7
5-5
4-4
1-1
0-0
8-6
7-5
10-7
10-5
8-3
7-2
5-0
10-2
5-2
4-1
10-4
8-0
9-0
9-9
9-6
9-4
9-1
9-7
9-3
6-6
6-4
6-3
6-0
6-1
3-1
3-0
3-3
10-9
10-6
4-0
5-1
8-4
7-3
9-5
6-2
10-3
8-1
7-0
9-2
竖着得数不变
被减数和减数都递减1
1-0
2-1
5-4
8-7
7-6
4-3
9-8
6-5
3-2
10
9
8
7
6
5
4
3
2
0
1
6-6
10-10
1-0
2-1
5-4
10-9
10-8
9-7
6-4
3-1
5-3
2-0
3-0
6-3
7-4
10-6
4-0
5-1
9-3
6-0
7-1
9-0
10-1
10-0
这个表怎么填?
9-9
8-8
7-7
4-4
3-3
1-1
0-0
9-8
8-7
7-6
4-3
8-6
10-7
9-6
8-4
9-4
8-3
6-1
5-0
10-3
8-1
7-0
9-1
4-1
7-3
10-4
8-0
5-5
6-5
7-5
9-5
10-5
3-2
7-2
9-2
10-2
5-2
6-2
8-5
8-2
4-2
2-2
斜着得数递减1
被减数递减1减数不变
21cnjy.com
10
9
8
7
6
5
4
3
2
0
1
2-2
6-6
10-10
1-0
2-1
10-9
10-8
9-7
6-4
3-1
5-3
3-0
6-3
8-5
10-6
4-0
9-3
6-0
7-1
9-0
10-1
10-0
没有规律了怎么做?
9-9
8-8
7-7
5-5
4-4
3-3
1-1
0-0
9-8
8-7
7-6
6-5
4-3
3-2
8-6
7-5
10-7
9-6
9-5
8-4
10-5
9-4
8-3
7-2
6-1
5-0
10-3
9-2
8-1
7-0
10-2
9-1
5-2
4-1
7-3
6-2
10-4
8-0
4-2
7-4
2-0
5-1
8-2
5-4
真棒
数一数铅笔的个数。
5
4
3
2
1
连一连
6-( )=8-( )
有几种填法
7-( )=4-( )
6-( )=8-( )
6-( )=8-( )
6-( )=8-( )
6-( )=8-( )
6-( )=8-( )
1
3
2
4
5
3
4
6
5
7
7-( )=4-( )
7-( )=4-( )
7-( )=4-( )
7-( )=4-( )
4
1
5
2
6
3
7
4
6-( )=8-( )
6
8
0
2
0
3
作业:同学们,10以内的加减法我们就学完了,需要多加练习才能算得更快更准,才能百尺竿头更进一步,千万别骄傲。
Thank you!