Tub sonlar

Tub son — faqat ikkita bo'luvchisi bor son: 1 va o'zi. Masalan 7 ni faqat 1 ga va 7 ga bo'lish mumkin. Ikkitadan ko'p bo'luvchisi bo'lgan son murakkab deyiladi: 12 ning bo'luvchilari 1, 2, 3, 4, 6, 12.

1 na tub, na murakkab: uning bo'luvchisi bitta. 2 — eng kichik tub son va yagona juft tub son, chunki qolgan hamma juft son 2 ga bo'linadi.

100 gacha 25 ta tub son bor, 1000 gacha — 168 ta. Ularning soni cheksiz: eng katta tub son yo'q.

Yechish tartibi

Son tub ekanini tekshirish: uning kvadrat ildizidan katta bo'lmagan tub sonlarga bo'lib ko'ring.
Masalan 97: √97 ≈ 9,8 — ya'ni 2, 3, 5, 7 ga bo'linishini tekshirish kifoya. Hech biriga bo'linmadi — 97 tub son.
Bo'linish belgilari ishni tezlashtiradi: oxirgi raqam juft bo'lsa yoki 5 bo'lsa, son darhol tub emas.

100 gacha tub sonlar

0–19	20–39	40–59	60–79	80–99
2	23	41	61	83
3	29	43	67	89
5	31	47	71	97
7	37	53	73
11		59	79
13
17
19

Dastlabki 20 ta tub son

№	Tub son	№	Tub son
1	2	11	31
2	3	12	37
3	5	13	41
4	7	14	43
5	11	15	47
6	13	16	53
7	17	17	59
8	19	18	61
9	23	19	67
10	29	20	71

Savol va javob

1 tub sonmi?

Yo'q. Tub sonning ikkita bo'luvchisi bo'lishi kerak, 1 ning esa bittasi — o'zi.

Eng kichik tub son qaysi?

2. U yana yagona juft tub son.

100 gacha nechta tub son bor?

25 ta: 2, 3, 5, 7, 11, 13, 17, 19, 23, 29 va boshqalar.

Tub va murakkab son nimasi bilan farq qiladi?

Tub sonning ikkita bo'luvchisi bor (1 va o'zi), murakkab sonning ikkitadan ko'p.

№	Tub son	№	Tub son
1	2	11	31
2	3	12	37
3	5	13	41
4	7	14	43
5	11	15	47
6	13	16	53
7	17	17	59
8	19	18	61
9	23	19	67
10	29	20	71

№	Tub son	№	Tub son
1	2	11	31
2	3	12	37
3	5	13	41
4	7	14	43
5	11	15	47
6	13	16	53
7	17	17	59
8	19	18	61
9	23	19	67
10	29	20	71

№	Tub son	№	Tub son
1	2	11	31
2	3	12	37
3	5	13	41
4	7	14	43
5	11	15	47
6	13	16	53
7	17	17	59
8	19	18	61
9	23	19	67
10	29	20	71