2024年4月12日发(作者:今年高考数学试卷是几卷)
小学一年级上册数学试题
加法 与 减法
进位加法(凑十法口诀:看大数,分小数,凑成十,算得数.)
退位减法(破十法口诀:看大数,分出10,减小数,加剩数.)
借十法(十几减9,几加1;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;十几减1,几加9.)
一.“凑十法”:
1.“凑十法”是20以内进位加法的根本思绪.应用“凑十法”可以或许将20以
内的进位加法转化为学生所熟习的10加几的标题,从而化难为简.
那么“凑十法”在具体盘算中是若何“凑”十的呢,我们看以下例题:
在盘算9+4时,先把4分成1和3,然后9和1凑成10,10再加上3等于13;
这就是“凑十法”.
2.“凑十歌”:
1凑9 2凑8 3凑7来4凑6 5.5相凑正满10 做减做加想到它,又对又快真便
利!
3.“凑十法”具有很强的纪律性,不但可以在解决20以内进位加法的盘算顶用
到,在不进位加法中也可以用到.以下边例子解释:如在盘算14+5时,先把14分
成10和4,然后4和5先加等于9,然后再和前边的10相加等于19;
二、
“借十法”(破十法):
1.“借十法”是用在20以内退位减法中的盘算办法.应用“借十法”可将20以
内的退位减法转化为学生所熟习的10减几的标题,从而化难为简.
那么“借十法”在具体盘算中是若何“凑”十的呢,我们看以下例题:
在盘算13减4时,先斟酌个位3减4,不敷减,于是从十位借10来减,10减4得
6,再用6与个位数3相加等于9;
这就是“借十法”.
2.“借十法”口诀:借十法,很简略;
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;十几减1,几加9.
3.依据口诀与例题控制“借十法”.
凑 十 歌
一九一九好同伙, 二八二八手拉手, 三七三七真密切, 四六四六一路走. 五五
凑成一双手.
一加九,十只小蝌蚪, 二加八,十只花老鸭, 三加七,十只老母鸡, 四加六,十只
金丝猴, 五加五,十只大山君.
看到9想到1, 看到8想到2, 看到7想到3, 看到6想到4. 看到大数加小
数,.
一五6,二四6,三三6,四二6,五一6;6的构成没漏掉.
一六7,二五7,三四7,四三7,五二7,六一7;7的构成记细心.
一七8,二六8,三五8,四四8,五三8,六二8,七一8;8的构成记全它.
一八9,二七9,三六9,四五9,五四9,六三9,七二9,八一9; 9的构成全都有.
一九10,二八10,三七10,四六10,五五10,六四10,七三10,八二10,九一
10;10的构成共九句.
【 练 习 题. 一 】 (凑 十 法)
9 + 6 = 9 + 5 = 9 + 4 =
9 + 3 = 9 + 2 = 9 + 7 =
9 + 8 = 9 + 9 = 8 + 8 =
8 + 7 = 8 + 9 = 8 + 6 =
8 + 5 = 8 + 4 = 8 + 3 =
7 + 9 = 7 + 8 = 7 + 7 =
7 + 6 = 7 + 4 = 7 + 5 =
6 + 9 = 6 + 8 = 6 + 7 =
6 + 6 = 6 + 5 = 5 + 9 =
5 + 8 = 5 + 7 = 5 + 6 =
4 + 9 = 4 + 8 = 4 + 7 =
3 + 9 = 3 + 8 = 2 + 9 =
【 练 习 题. 二 】 (破十法)
11
– 9 = 17 – 9 = 16 – 9 = 15
12
–
–
9 = 13
4=
– 9 = 12 – 9 = 11
11
–
– 3 =
–
8 = 16
3 =
– 8 = 15 – 8 = 14
11
–
–
8 = 12
2 =
– 8 = 11 – 8 = 16
11
–
–
7 = 14
5 =
– 7 = 13 – 7 = 12
12
–
–
7 = 15
4=
– 6 = 14 – 6 = 13
13
– 6 = 11
– 4=
– 6 = 14 – 5 = 13
【 练 习 题. 三 】 (20以内退位减法)
破十法口诀:看大数,分出10;减小数,加剩数.
15 - 6 = 12 - 5 = 17
13 - 4 = 11 - 5 = 14
16 - 8 = 15 - 9 = 18
12 - 7 = 14 - 9 = 13
12 - 9 = 11 - 3 = 12
16 - 9 = 15 - 8 = 13
11 - 6 = 13 - 4 = 14
13 - 9 = 17 - 8 = 14
– 9 =
– 9 =
– 8 =
– 7 =
– 7 =
– 6 =
– 5 =
- 9 =
- 7 =
- 9 =
- 7 =
- 4 =
- 8 =
- 5 =
- 6=
18
14
17
13
15
11
12
【 练 习 题. 四 】 (凑十法)
1. 拆小数,凑大数
9 + 9 = 9 + 8 = 9 + 7 =
9 + 6 = 9 + 5 = 9 + 4 =
9 + 3 = 9 + 2 = 8 + 8 =
8 + 7 = 8 + 6 = 8 + 5 =
8 + 4 = 8 + 3 = 7 + 7 =
7 + 6 = 7 + 5 = 7 + 4 =
6 + 6 = 6 + 5 =
2. 拆大数,凑小数
9 + 9 = 8 + 9 = 7 + 9 =
6 + 9 = 5 + 9 = 4 + 9 =
3 + 9 = 2 + 9 = 8 + 8 =
7 + 8 = 6 + 8 = 5 + 8 =
4 + 8 = 3 + 8 = 7 + 7 =
6 + 7 = 5 + 7 = 4 + 7 =
6 + 6 = 5 + 6 =
15 - 6 = 14 - 5 = 13 - 4 =
【 练 习 题. 五 】 (凑十法)
【 练 习 题. 六 】 (凑十法)
【 练 习 题. 七 】 (凑十法)
【 练 习 题. 八 】 (凑十法)
12 - 3 = 11 - 2 = 16 - 7 =
17 - 8 = 18 - 9 = 16 - 8 =
15 - 7 = 17 - 9 = 14 - 6 =
13 - 5 = 12 - 4 = 11 - 3 =
16 - 9 = 15 - 8 = 14 - 7 =
13 - 6 = 11 - 4 = 12 - 5 =
15 - 9 = 14 - 8 = 13 - 7 =
12 - 6 = 11 - 5 = 14 - 9 =
13 - 8 = 12 - 7 = 11 - 6 =
13 - 9 = 12 - 8 = 11 - 7 =
12 - 9 = 11 - 8 = 11 - 9 =
【 练 习 题. 九 】 (凑十法)
1. 拆小数,凑大数,凑成10,再相加 .
9 + 8 = 9 + 7 = 9 + 6 =
9 + 5 = 9 + 4 = 9 + 3 =
9 + 2 = 8 + 7 = 8 + 6 =
8 + 5 = 8 + 4 = 8 + 3 =
7 + 6 = 7 + 5 = 7 + 4 =
6 + 5 =
【 练 习 题. 十 】 (凑十法)
2. 拆大数,凑小数,凑成10,再相加 .
8 + 9 = 7 + 9 = 6 + 9 =
5 + 9 = 4 + 9 = 3 + 9 =
2 + 9 = 7 + 8 = 6 + 8 =
5 + 8 = 4 + 8 = 3 + 8 =
6 + 7 = 5 + 7 = 4 + 7 =
5 + 6 =
3.
9 + 9 = 8 + 8 = 7 + 7 =
6 + 6 =
1. 拆小数,凑大数
9 + 9 = 9 + 8 = 9 + 7 =
9 + 6 = 9 + 5 = 9 + 4 =
9 + 3 = 9 + 2 = 8 + 8 =
8 + 7 = 8 + 6 = 8 + 5 =
8 + 4 = 8 + 3 = 7 + 7 =
7 + 6 = 7 + 5 = 7 + 4 =
6 + 6 = 6 + 5 =
2. 拆大数,凑小数
9 + 9 = 8 + 9 = 7 + 9 =
6 + 9 = 5 + 9 = 4 + 9 =
3 + 9 = 2 + 9 = 8 + 8 =
7 + 8 = 6 + 8 = 5 + 8 =
4 + 8 = 3 + 8 = 7 + 7 =
6 + 7 = 5 + 7 = 4 + 7 =
6 + 6 = 5 + 6 =
练 习 题. 十一 】 (凑十法)
练 习 题. 十二 】 (凑十法)
【
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