YUz ichidagi, sonlarni qo‟shishning og‟zaki usullarini o‟rganish davrida
24
(4 + 2) + 3 = 6 + 3 = 9
(4 + 2) + 3 = (4 + 3) + 2 = 7 + 2 = 9
(4 + 2) + 3 = 4 + (3 + 2) = 4 + 5 = 9
Bu qoidaga asosan
34 + 2 ko‟rinishidagi misollarni ishlash 34 +20 o‟rgatiladi va ikkala ishlash holi bir-
biriga taqqoslab ko‟rsatiladi.
Tushuntirish bunday tartibda olib boriladi: oldin sonni yig‟indi bilan almashtiraman,
yig‟indini songa qo‟shish hosil bo‟ladi, so‟ngra eng qulay usul bilan echamiz.
34 + 2 = (30 + 4) + 2 = 30 + (4 + 2) = 36
34 + 20 = (30 + 4) + 20 = (30 + 20) + 4 = 54
Bu ko‟rinishdagi misollar ko‟p marta ishlanishi natijasida o‟quvchida ko‟nikma hosil
bo‟ladi, so‟ngra xisoblash usuli qisqartiriladi:
Masalan 42 + 30; 42 va 30 qo‟shish uchun 40 ga 30 ga qo‟shamiz bu 70 yana 2,
shuning uchun 72 bo‟ladi va 42 + 30 = 72 deb yoziladi. Vaqti-vaqti bilan to‟la
tushuntirishlarni so‟rab borish kerak.
Ayirish.
2ўн
=
2
4
20
40
ўн
ўн
2 o‟n = 20
40-20 = 20
45-5 = (40 + 5)-5 = 40 + (5-5) = 40
45-40 = (40 + 5)-40 = (40-40) + 5 = 5
45-3 = (40 + 5)-3 = 40 + (5-3) = 40 + 2 = 42
3
5
40
3
45
5
10
30
10
30
=
40
5
40
deb olamiz
40 + (5-3) = 40 + 2 = 42
30 + (10-5) = 30 + 5 = 35
36
=
4
-
40
=
4
5
-
45
=
4
5
-
45
=
9
45
5
30
40
30
5
40
30
45
22
=
3
-
25
=
3
20
-
45
=
3
20
45
23
45
17
=
8
-
25
=
8
20
-
45
=
8
20
45
28
45
18 ichidagi bir xonali sonlarni o‟nlikdan o‟tish bilan qo‟yish.
8 + 3 =11
7 + 4 = 11
8 + 2 + 1
7 + 3 + 1
11
2
9
4
9
2
11
9
3
9
1
4
6
5
6
2
2
8
4
8
13
2
11
11
2
9
1
2
8
3
8
3
1
9
4
9
1
3
7
=
4
7
3
2
8
5
8
4
2
8
6
8
2
4
6
6
6
3
3
7
6
7
25
5
2
8
7
8
6
1
9
7
9
4
3
7
7
7
6
2
8
8
8
7
1
9
8
9
8
1
9
9
9
18 ichidagi jadval hosil bo‟ladi.
Ayirish.
11-3 = 8
13-4 = 9
11-1-2
13-3 = 10
15-7 = 8
15 = 7 + 8
15-5-2
15-7 = 8
15-8 = 7
13-8 = 5
11-4 = 7
17-9 = 8
8 + 5
7 + 4
9 8
3
-
1
11
4
11
7
=
4
11
7
4
=
11
11-7 = 4
7
1
11
8
11
3
=
8
11
3
8
=
11
11-3 = 8
3
2
12
5
12
7
=
5
12
7
5
=
12
12-7 = 5
7
2
12
9
12
3
=
9
12
3
9
=
12
12-3 = 9
2
3
13
5
13
8
=
5
13
8
5
=
13
13-8 = 5
6
3
13
9
13
4
=
9
13
4
9
=
13
13-4 = 9
5
4
14
9
14
5
=
9
14
5
9
=
14
14-5 = 9
3
5
15
8
15
1
6
16
7
16
9
=
7
16
9
7
=
16
16-9 = 7
38 + 5
43 + 8
2 3
7
1
38 + 2 + 3
43 +7 + 1
(38 + 2) + 3
(43 + 7) + 1
40 + 3 = 43
50 + 1 = 51
26 + 7 = 33
26 + 7 = (26 + 4) + 3 = 30 + 3 = 33
4 3
42-5
43-8
91 - 8
2 3
3
5
1 7
42-2-3
43-3-5
91-1-7
(42-2)-3
43-3 = 40
91-1 = 90