There are ten main Incarnations of Lord Vishnu (Avataar):
(1) Matsya Avataar (The Fish Incarnation),
(2) Koorm Avataar (The Tortoise Incarnation),
(3) Varaah Avataar (The Boar Incarnation)
(4) Narasinh Avataar (The Man with Lion Head Incarnation),
(5) Vaaman Avataar (The Dwarf Incarnation, Vaaman means 52 so
     this Avataar was only a 52 finger-width tall child),
(6) Parashuraam Avataar (The Raam with Axe Incarnation),
(7) Raam Avataar (The Raam Incarnation in Soorya Vansh)
(8) Krishn Avataar (The Krishn Incarnation in Chandra Vansh)
(9) Buddha Avataar (The Gautam Buddha Incarnation)
(10) Kalki Avataar - Yet to come, will be at the end of the Kali Yug to bring Sat Yug.

There are ten types of Vaayu (wind) in our body: Praan, Apaan, Samaan, Udayaan, Vayaan, Naag, Karm, Krikaal, Devadatt, Dhananjaya. When Praan Vaayu goes out of the body, we die.

If the 10 Indriyaan (given below in Number Eleven section) of human body are Shuddh (without any evil) then they are called ten Vairaagin.

There are 10 directions - (1) Uttar (North) (2) Uttar-Poorv (Northeast, (3) Poorv (East), (4) Dakshin-Poorv (Southeast), (5) Dakshin (South), (6) Dakshin-Pashchim (Southwest), (7) Paschim (West), (8) Pashchim-Uttar or Pashchimottar (Northwest) (9) Sky above, and (10) Paataal down.

There are 10 Mahaa-vidyaa -
(1) Kaalee - Devourer of Time (Supreme Deity of Kaalee Kul Systems)
(2) Taaraa - the Goddess as Guide and Protector
(3) Lalitaa Tripur-sundaree - Shodashee - The most beautiful in the three worlds (Supreme Deity of Shree Kul Systems). The Taantrik Paarvatee or Moksh Mukutaa
(4) Bhuvaneshwaree - The Goddess as World Mother
(5) Bhairavee - the fierce Goddess
(6) Chinnmastaa - the Self-Decapitated Goddess
(7) Dhoomaavatee - the Widow Goddess
(8) Bagalaamukhee - The Goddess who paralyzes enemies
(9) Maatangee - the Prime Minister of Lalitaa, the Taantrik Saraswatee
(10) Kamalaa - the Lotus Goddess, the Taantrik Lakshmee

There were 10 heads of Raavan.

There are eleven Indriyaan (senses) in our body - five Gyaan Indriyaan, five Karm Indriyaan and one Man or Hridaya (Heart) governing all of them.

Gyaan Indriyaan gives us knowledge - eyes by seeing, ears by hearing, skin by touching, nose by smelling, and tongue by tasting.

Karm Indriyaan are for doing daily duties of our life - hands to donate something to somebody, feet to go to Bhagavaan's Darshan, tongue to sing Bhagavaan's songs, anus to excrete solid wastage, procreation organs,

Above all is Man or mind which controls all these Indriyaan. If Man wants, it can control the action of all these ten Indriyaan. That is why it is said that "If you have control on your Man, you have control on your body."

Many people keep fast on Ekaadashee (11th day of every fortnight). It reminds one to control one's eleven Indriyaan.

12 Signs (Asrological)
There are twelve Raashi (Signs) through which the nine Grah (planets) travel. The total time period of this travel is calculated as 120 years. These Raashi are:

(1) Mesh - Aries,
(2) Vrishabh - Taurus,
(3) Mithun - Gemini,
(4) Kark - Cancer,
(5) Sinh - Leo,
(6) Kanyaa - Virgo,
(7) Tulaa -
(8) Vrishchik - Scorpio,
(9) Dhanu - Saggitarius,
(10) Makar - Capricorn,
(11) Kumbh - Aquarius,
(12) Meen - Pisces

Every Grah (Planet) has a different time span for each Raashi. These 12 Raashi are equally distributed around the Earth - 30 degrees each.

12 Solar Months
There are twelve Maas (Months) in a year. Everybody knows that the Sun revolves around the Earth and it takes 12 months or one year to come to the same place. These months are :--

12 Hindu Lunar Months
In the same way Moon also travels through these Raashi (signs). But it takes only a little more than 29 days in each Raashi, so it also takes one year, but a little less than the Solar Year. These months are :--

In Christianity, Thirteen number is a bad number and omen. Because when Jesus had his Last Supper, they were Thirteen people on the table.

Julian calendar has Thirteen Months. Ethiopians observe this calendar. In this calendar all Twelve Months are of 30 days each, but then they have a short Thirteenth Month of 5 days. This calendar starts from September 11.

Many hotels do not have room number 13, and floor number 13.
In many countries, there is no Gate 13 at any airport, instead there is a gate 12B.
Some airplanes skip a row 13, going straight from 12 to 14.
Many tall buildings have resorted to skipping the "thirteenth floor", either by numbering it "14" or as "12".
Some streets do not contain a house number 13.
In some forms of motor sport, for example Formula One, there is no number 13 car.
Getting married on any day of the week that falls under number 13 is highly discouraged.
In Egypt Tarot Cards there is a picture number 13, which symbolizes "Death".

There are fourteen Lok (worlds) - seven in Aakaash (sky) and seven in Paataal (below this earth).

Names of seven Paataal Lok:   Atal, Sutal, Vital, Talaatal, Mahaatal, Rasaatal, Paataal. These Lok are imagined in human body also. And their placement is below navel, up to feet.

Names of seven Aakaash Lok:  Bhoo, Bhuvah, Swah, Mah, Jan, Tap, Satya. Their placement in the human body is from navel to head.

Bhoo Lok in navel,
Bhuvah Lok in stomach,
Swah Lok in heart,
Mah Lok in throat,
Jan Lok in mouth,
Tap Lok in forehead,
Satya Lok in the breath hole in the center of the forehead.

There are twenty-seven Nakshatra (Constellations) in the sky which also make up the twelve Raashi (Signs) - 2 and 1/3 Nakshatra for each Sign.

There are thirty Days in a month.

There are 84 Aasan (positions) in Indian Yog.

There are 84 Laakh (840,000) Yoni (species) passing through which a soul takes human birth.

There are one hundred and eight beads in the Maalaa (Rosary) which Hindu use for counting their Jaap (in Jaap the same word or Mantra is repeated several times, this Maalaa is used to count those words or Mantra).

There are 54 letters in Sanskrit alphabet; and if you write them from both sides, they become 108 in number.