(共12张PPT)
整理和复习
我会用破十法来算
18
–9=
11
–
2=
14
–
8=
15
–
6=
8
10
1
9
1
10
8
9
4
10
2
6
5
10
4
9
我会用破十法来算
3
10
5
8
4
10
3
7
1
10
7
8
2
10
6
13
–
5=
14
–7=
11
–3=
12
–
4=
8
儿歌
退位减法我会算
十几减9,几
加
1
十几减8,几
加
2
十几减7,几
加
3
十几减6,几
加
4
十几减5,几
加
5
十几减4,几
加
6
十几减3,几
加
7
十几减2,几
加
8
20以退位减法表
11-9
12-9
13-9
14-9
15-9
16-9
17-9
18-9
11-8
11-7
11-6
11-5
11-4
11-3
11-2
十几减9
十几减8
十几减7
十几减6
十几减5
十几减4
十几减3
十几减2
你
能
说
出
空
白
的
算
式吗?
12-8
13-8
14-8
15-8
16-8
17-8
12-7
13-7
14-7
15-7
16-7
12-6
12-5
12-4
12-3
13-6
14-6
15-6
13-5
13-4
14-5
竖
着
看
-9=
-9=
-9=
-9=
-9=
-9=
-9=
-9=
减数不变,
11
12
13
14
15
16
17
18
被减数变大,
2
3
4
5
6
7
8
9
差也变大。
横
着
看
11-
=
11-
=
11-
=
11-
=
11-
=
11-
=
11-
=
11-
=
9
8
7
6
5
4
3
2
被减数不变,
2
3
4
5
6
7
8
9
减数变小,
差变大。
12-3=
13-4=
14-5=
15-6=
16-7=
17-8=
18-9=
11-2=
斜着看,结果相等
9
9
9
9
9
9
9
9
找
朋
友
找出得数相同的卡片
13-9
12-8
12-4
11-7
14-6
15-7
15-9
16-8
12-6
13-7
11-3
17-9
11-5
口算接龙
vv
1111
13
5
9
18
10
15
8
6+
14
3-
11
8+
19
6-
13
5-
8
7+
15
13
+5
18
-7
11
+4
15
-5
10
2+
12
4-
8
9+
17
3-
14
6+
20
-7
-2
-8
+4
+9
-8
+5
(1)读一读,你知道了什么?
(2)要解决这个问题,得知道什么?
小猫去河边垂钓,经过努力小猫带着收获回来了。
17-9=8(条)
(3)能列个算式吗?
(4)为什么用减法算?
(6)根据所给的信息,你能提出其他的数学问题并解答吗?
(5)解答正确吗?
问题:
我会用
口答:
少8条。
谢
谢(共16张PPT)
整理和复习
11
-
9
11
-
8
11
-
7
11
-
6
11
-
5
11
-
4
11
-
3
11
-
2
12
-
9
12
-
8
12
-
7
12
-
6
12
-
5
12
-
4
12
-
3
13
-
9
13
-
8
13
-
7
13
-
6
13
-
5
13
-
4
14
-
9
14
-
8
14
-
7
14
-
6
14
-
5
15
-
9
15
-
8
15
-
7
15
-
6
16
-
9
16
-
8
16
-
7
17
-
9
17
-
8
18
-
9
20
以内退位减法表
横着看,第一行
都是
11
减几。
11减几
12减几
13减几
14减几
15减几
16减几
17减几
18减几
11
-
9
11
-
8
11
-
7
11
-
6
11
-
5
11
-
4
11
-
3
11
-
2
12
-
9
12
-
8
12
-
7
12
-
6
12
-
5
12
-
4
12
-
3
13
-
9
13
-
8
13
-
7
13
-
6
13
-
5
13
-
4
14
-
9
14
-
8
14
-
7
14
-
6
14
-
5
15
-
9
15
-
8
15
-
7
15
-
6
16
-
9
16
-
8
16
-
7
17
-
9
17
-
8
18
-
9
2
3
4
5
6
7
8
9
被减数不变,减数变小,差变大
横着看,第一行的得数有什么规律?
11
-
2
11
-
3
12
-
3
11
-
4
12
-
4
13
-
4
11
-
5
12
-
5
13
-
5
14
-
5
11
-
6
12
-
6
13
-
6
14
-
6
15
-
6
11
-
7
12
-
7
13
-
7
14
-
7
15
-
7
16
-
7
11
-
8
12
-
8
13
-
8
14
-
8
15
-
8
16
-
8
17
-
8
11
-
9
12
-
9
13
-
9
14
-
9
15
-
9
16
-
9
17
-
9
18
-
9
20
以内退位减法表
竖着看,第一列
都是减
9
的。
十几减9
十几减8
十几减7
十几减6
十几减5
十几减4
十几减3
十几减2
11
-
9
11
-
8
11
-
7
11
-
6
11
-
5
11
-
4
11
-
3
11
-
2
12
-
9
12
-
8
12
-
7
12
-
6
12
-
5
12
-
4
12
-
3
13
-
9
13
-
8
13
-
7
13
-
6
13
-
5
13
-
4
14
-
9
14
-
8
14
-
7
14
-
6
14
-
5
15
-
9
15
-
8
15
-
7
15
-
6
16
-
9
16
-
8
16
-
7
17
-
9
17
-
8
18
-
9
2
3
4
5
6
7
8
9
被减数变大,减数不变,差变大
那竖着看你又发现了什么?
.
你还能发现什么有规律的排列?
11
-
9
11
-
8
11
-
7
11
-
6
11
-
5
11
-
4
11
-
3
11
-
2
12
-
9
12
-
8
12
-
7
12
-
6
12
-
5
12
-
4
12
-
3
13
-
9
13
-
8
13
-
7
13
-
6
13
-
5
13
-
4
14
-
9
14
-
8
14
-
7
14
-
6
14
-
5
15
-
9
15
-
8
15
-
7
15
-
6
16
-
9
16
-
8
16
-
7
17
-
9
17
-
8
18
-
9
算一算,你会有更多的发现。
11
-
9
11
-
8
11
-
7
11
-
6
11
-
5
11
-
4
11
-
3
11
-
2
12
-
9
12
-
8
12
-
7
12
-
6
12
-
5
12
-
4
12
-
3
13
-
9
13
-
8
13
-
7
13
-
6
13
-
5
13
-
4
14
-
9
14
-
8
14
-
7
14
-
6
14
-
5
15
-
9
15
-
8
15
-
7
15
-
6
16
-
9
16
-
8
16
-
7
17
-
9
17
-
8
18
-
9
你还可以怎样看?
3
4
5
6
7
8
9
4
5
5
6
6
6
7
7
7
7
8
8
8
8
8
9
9
9
9
9
9
斜着看,被减数变大,减数也随之变大,差不变。
2
3
5
8
4
6
7
9
小朋友们,你们能把差是
6
的算式一组一组地说出来吗?
11-5=6
12-6=6
13-7=6
14-8=6
15-9=6
10-4=6
9-3=6
8-2=6
7-1=6
让我来考考你吧。
儿歌
退位减,我会算
十几减9,是几加1,
十几减8,是几加2,
十几减7,是几加3,
十几减6,是几加4,
十几减5,是几加5。
智勇大冲关
第一关:看图列算式
+
=
7
5
12
+
=
5
7
12
-
=
12
7
5
-
=
12
5
7
+
=
8
7
15
+
=
7
8
15
-
=
15
8
7
-
=
15
7
8
第二关:想加算减
3
+
8
=
11
-
3
=
11
-
8
=
4
+
9
=
13
-
4
=
13
-
9
=
5
+
7
=
12
-
5
=
12
-
7
=
11
8
3
13
9
4
12
7
5
11
-
8
12
-
6
13
-
7
14
-
9
15
-
9
12
-
7
13
-
8
11
-
6
第三关:争小红旗
第四关:争当神算手
9
+
8
=
11
-
6
=
16
-
9
=
15
-
7
=
3
+
8
=
12
-
5
=
12
-
6
=
8
+
7
=
15
-
6
=
14
-
5
=
7
+
7
=
14
-
6
=
14
-
8
=
13
-
6
=
7
+
9
=
6
+
6
=
13
-
7
=
12
-
9
=
17
6
6
5
15
7
7
9
16
8
9
12
11
14
6
7
8
3
头好晕啊!我投降了
17
-
8
-
3
=
11
-
6
+
7
=
5
+
4
+
6
=
9
+
4
-
6
=
5
+
9
-
8
=
8
+
7
-
9
=
6
12
15
7
6
6
第五关:看谁最棒
谢
谢(共17张PPT)
整理和复习
破十法
想加算减
连减法
多余条件
一个数比另一个数多(少)几?
减法
13
–
4
12
–
3
11
–
2
11
–
3
12
–
4
12
–
5
12
–
9
12
–
6
12
–
7
12
–
8
11
–
5
11
–
6
11
–
7
11
–
9
11
–
8
11
–
4
13
–
5
13
–
6
13
–
7
13
–
8
13
–
9
14
–
9
14
–
6
14
–
5
14
–
7
14
–
8
17
–
9
15
–
7
15
–
9
15
–
8
15
–
6
16
–
7
16
–
9
16
–
8
17
–
8
18
–
9
11
–
2
11
–
3
11
–
5
11
–
6
11
–
7
11
–
9
11
–
8
11
–
4
12
–
9
13
–
9
14
–
9
17
–
9
15
–
9
16
–
9
18
–
9
小组活动1
按一定的顺序摆出退位减法表。
活动要求:
1、小组合作先计算出所有的算式。
2、想一想排列的方法和顺序
,再合作排列出退位减法表。
13
–
4
=
9
12
–
3=
9
11
–
2
=
9
11
–
3
=
8
12
–
4
=
8
12
–
5
=
7
12
–
9
=
3
12
–
6
=6
12
–
7
=
5
12
–
8
=
4
11
–
5
=
6
11
–
6
=
5
11
–
7
=
4
11
–
9
=
2
11
–
8
=
3
11
–
4
=
7
13
–
5
=
8
13
–
6
=
7
13
–
7
=
6
13
–
8
=
5
13
–
9
=
4
14
–
9
=
5
14
–
6
=
8
14
–
5
=
9
14
–
7
=
7
14
–
8=
6
17
–
9
=
8
15
–
7
=
8
15
–
9
=
6
15
–
8=
7
15
–
6
=
9
16
–
7
=
9
16
–
9
=
7
16
–
8=
8
17
–
8
=9
18
–
9
=
9
小组活动2
观察表格,发现规律。
活动要求:
先从不同方向观察减法表,再把你的发现和同组同学说一说。
观察表格,发现规律
11
–
2
=
9
11
–
3
=
8
11
–
5
=
6
11
–
6
=
5
11
–
7
=
4
11
–
9
=
2
11
–
8
=
3
11
–
4
=
7
13
–
4
=
9
12
–
3=
9
12
–
4
=
8
12
–
5
=
7
12
–
9
=
3
12
–
6
=6
12
–
7
=
5
12
–
8
=
4
13
–
5
=
8
13
–
6
=
7
13
–
7
=
6
13
–
8
=
5
13
–
9
=
4
14
–
9
=
5
14
–
6
=
8
14
–
5
=
9
14
–
7
=
7
14
–
8=
6
17
–
9
=
8
15
–
7
=
8
15
–
9
=
6
15
–
8=
7
15
–
6
=
9
16
–
7
=
9
16
–
9
=
7
16
–
8=
8
17
–
8
=9
18
–
9
=
9
-1
-1
-1
-1
-1
-1
-1
+1
+1
+1
+1
+1
+1
+1
11
11
11
11
11
11
11
11
横着看
被减数不变,
减数连续减1,
差连续加1。
观察表格,发现规律
11
–
2
=
9
11
–
3
=
8
11
–
5
=
6
11
–
6
=
5
11
–
7
=
4
11
–
9
=
2
11
–
8
=
3
11
–
4
=
7
12
–
3=
9
12
–
4
=
8
12
–
5
=
7
12
–
9
=
3
12
–
6
=6
12
–
7
=
5
12
–
8
=
4
13
–
4
=
9
13
–
5
=
8
13
–
6
=
7
13
–
7
=
6
13
–
8
=
5
13
–
9
=
4
14
–
9
=
5
14
–
6
=
8
14
–
5
=
9
14
–
7
=
7
14
–
8=
6
17
–
9
=
8
15
–
7
=
8
15
–
9
=
6
15
–
8=
7
15
–
6
=
9
16
–
7
=
9
16
–
9
=
7
16
–
8=
8
17
–
8
=9
18
–
9
=
9
-1
-1
-1
-1
-1
-1
-1
+1
+1
+1
+1
+1
+1
+1
11
11
11
11
11
11
11
11
横着看
被减数不变,
减数连续减1,
差连续加1。
观察表格,发现规律
13
–
4
=
9
12
–
3=
9
11
–
2
=
9
11
–
3
=
8
12
–
4
=
8
12
–
5
=
7
12
–
6
=6
12
–
7
=
5
12
–
8
=
4
11
–
5
=
6
11
–
6
=
5
11
–
7
=
4
11
–
8
=
3
11
–
4
=
7
13
–
5
=
8
13
–
6
=
7
13
–
7
=
6
13
–
8
=
5
14
–
6
=
8
14
–
5
=
9
14
–
7
=
7
14
–
8=
6
15
–
7
=
8
15
–
8=
7
15
–
6
=
9
16
–
7
=
9
16
–
8=
8
17
–
8
=9
12
–
9
=
3
11
–
9
=
2
13
–
9
=
4
14
–
9
=
5
17
–
9
=
8
15
–
9
=
6
16
–
9
=
7
18
–
9
=
9
9
9
9
9
9
9
9
9
+1
+1
+1
+1
+1
+1
+1
+1
+1
+1
+1
+1
+1
+1
竖着看
减数不变,
被减数连续加1,
差也连续加1。
观察表格,发现规律
13
–
4
=
9
12
–
3=
9
11
–
2
=
9
11
–
3
=
8
12
–
4
=
8
12
–
5
=
7
11
–
5
=
6
11
–
4
=
7
13
–
5
=
8
14
–
5
=
9
12
–
6
=6
12
–
7
=
5
11
–
6
=
5
11
–
7
=
4
13
–
6
=
7
13
–
7
=
6
14
–
6
=
8
14
–
7
=
7
15
–
7
=
8
15
–
6
=
9
16
–
7
=
9
12
–
8
=
4
11
–
8
=
3
13
–
8
=
5
14
–
8=
6
15
–
8=
7
16
–
8=
8
17
–
8
=9
12
–
9
=
3
11
–
9
=
2
13
–
9
=
4
14
–
9
=
5
17
–
9
=
8
15
–
9
=
6
16
–
9
=
7
18
–
9
=
9
9
9
9
9
9
9
9
9
+1
+1
+1
+1
+1
+1
+1
+1
+1
+1
+1
+1
+1
+1
竖着看
减数不变,
被减数连续加1,
差也连续加1。
观察表格,发现规律
11
–
3
=
8
12
–
4
=
8
12
–
5
=
7
12
–
9
=
3
12
–
6
=6
12
–
7
=
5
12
–
8
=
4
11
–
5
=
6
11
–
6
=
5
11
–
7
=
4
11
–
9
=
2
11
–
8
=
3
11
–
4
=
7
13
–
5
=
8
13
–
6
=
7
13
–
7
=
6
13
–
8
=
5
13
–
9
=
4
14
–
9
=
5
14
–
6
=
8
14
–
7
=
7
14
–
8=
6
17
–
9
=
8
15
–
7
=
8
15
–
9
=
6
15
–
8=
7
16
–
9
=
7
16
–
8=
8
13
–
4
=
9
12
–
3=
9
11
–
2
=
9
14
–
5
=
9
15
–
6
=
9
16
–
7
=
9
17
–
8
=9
18
–
9
=
9
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
9
9
9
9
9
9
9
9
斜着看
被减数和减数同时减(或加)1,差不变.
观察表格,发现规律
12
–
5
=
7
12
–
9
=
3
12
–
6
=6
12
–
7
=
5
12
–
8
=
4
11
–
5
=
6
11
–
6
=
5
11
–
7
=
4
11
–
9
=
2
11
–
8
=
3
11
–
4
=
7
13
–
6
=
7
13
–
7
=
6
13
–
8
=
5
13
–
9
=
4
14
–
9
=
5
14
–
7
=
7
14
–
8=
6
15
–
9
=
6
15
–
8=
7
16
–
9
=
7
11
–
3
=
8
12
–
4
=
8
13
–
5
=
8
14
–
6
=
8
17
–
9
=
8
15
–
7
=
8
16
–
8=
8
13
–
4
=
9
12
–
3=
9
11
–
2
=
9
14
–
5
=
9
15
–
6
=
9
16
–
7
=
9
17
–
8
=9
18
–
9
=
9
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
9
9
9
9
9
9
9
9
斜着看
被减数和减数同时减(或加)1,差不变.
数学城堡
第一关:开智慧门
11-6=(
)
11-7=(
)
11-8=(
)
(
)
-7=5
(
)
-7=6
(
)
-7=7
11-(
)=9
12-(
)=9
13-(
)=9
5
4
3
12
13
14
2
3
4
第二关:搭桥过河
不计算,按得数从小到大排一排
13
—
8
13
—
2
13
—
5
13
—
9
13
—
4
13
—
0
<
<
<
<
<
第三关:评选优胜组
比一比哪组红花多?
根据红花榜上的信息,提出数学问题。
这节复习课你有什么收获呢?
谢
谢(共20张PPT)
整理和复习
计算接力赛。
14-8=
13-6=
11-9=
17-8=
16-7=
15-6=
12-9=
11-5=
14-7=
11-3=
12-6=
13-8=
5
被减数
减数
差
…
…
…
激趣导入
打败小僵尸
13-8
14-7
16-7
11-9
11-4
14-6
12-6
12-9
13-7
15-8
12-7
15-6
16-8
18-9
11-6
12-3
18-9
16-5
11-9
13-6
返回
通关
找规律填一填
十几-9
十几-8
十几-7
十几-6
十几-5
十几-4
十几-3
十几-2
20以内的退位减法表
11-
8=3
11-
6=5
12-
8=4
12-
6=6
13-
8=5
13-
6=7
14-
8=6
14-
6=8
11-
4=7
11-
3=8
11-
2=9
12-
4=8
12-
3=9
13-
4=9
15-
8=7
15-
6=9
16-
8=8
17-
8=9
11-
9=2
12-
9=3
13-
9=4
14-
9=5
15-
9=6
16-
9=7
17-
9=8
18-
9=9
11-
7=4
12-
7=5
13-
7=6
14-
7=7
15-
7=8
16-
7=9
11-
5=6
12-
5=7
13-
5=8
14-
5=9
20以内的退位减法表
竖着看,你发现了什么?
减数不变,被减数越大,差也越大。
十几-9
十几-8
十几-7
十几-6
十几-5
十几-4
十几-3
十几-2
11-
9=2
11-
8=3
11-
7=4
11-
6=5
11-
5=6
11-
4=7
11-
3=8
11-
2=9
12-
9=3
12-
8=4
12-
7=5
12-
6=6
14-
9=5
14-
8=6
14-
7=7
14-
6=8
12-
5=7
12-
4=8
12-
3=9
14-
5=9
15-
9=6
15-
8=7
15-
7=8
15-
6=9
16-
9=7
16-
8=8
16-
7=9
17-
9=8
17-
8=9
18-
9=9
13-
9=4
13-
8=5
13-7=6
13-
6=7
13-
5=8
13-
4=9
20以内的退位减法表
横着看,有什么发现?
被减数不变,减数越小,差越大。
11减几
12减几
13减几
14减几
15减几
16减几
17减几
18减几
11-
9=2
11-
8=3
11-
7=4
11-
6=5
11-
5=6
11-
4=7
11-
3=8
11-
2=9
12-
9=3
12-
8=4
12-
7=5
12-
6=6
14-
9=5
14-
8=6
14-
7=7
14-
6=8
12-
5=7
12-
4=8
12-
3=9
14-
5=9
15-
9=6
15-
8=7
15-
7=8
15-
6=9
16-
9=7
16-
8=8
16-
7=9
17-
9=8
17-
8=9
18-
9=9
13-
9=4
13-
8=5
13-7=6
13-
6=7
13-
5=8
13-
4=9
被减数、减数依次增加1,差不变。
斜着看你能发现什么规律?
11-
9=2
11-
8=3
11-
7=4
11-
6=5
11-
5=6
11-
4=7
11-
3=8
11-
2=9
12-
9=3
12-
8=4
12-
7=5
12-
6=6
14-
9=5
14-
8=6
14-
7=7
14-
6=8
12-
5=7
12-
4=8
12-
3=9
14-
5=9
15-
9=6
15-
8=7
15-
7=8
15-
6=9
16-
9=7
16-
8=8
16-
7=9
17-
9=8
17-
8=9
18-
9=9
13-
9=4
13-
8=5
13-7=6
13-
6=7
13-
5=8
13-
4=9
20以内的退位减法表
被减数越大,减数也越大,差不变。
常用的方法:
1、算减法想加法
2、凑十法(连减法)
4、口诀法(儿歌)
3、破十法
思考:计算退位减法的方法都有哪些?
想加算减
12-9=
(
)
9+(
)=12
3
3
连减法
12-9=(
)
12-2-7=(
)
3
3
破十法
16
–
9
=
破十法
16-9=
16-9=
破十法
7
16
–
9
=
10
6
–
1
+
7
16-9=
破十法
儿歌
退位减,我会算
十几减9,等于几加1,
十几减8,等于几加2,
十几减7,等于几加3,
十几减6,等于几加4,
十几减5,等于几加5。
12-9=
13-8=
看谁算得又对又快!
17-9=
15-8=
13-9=
19-9=
任选方法进行计算:
这节课我们复习了什么内容
!
谢
谢