Chickenpox (Chicken Pox) , also known as Varicella, is a very contagious infection caused by the varicella zoster virus. In several parts of the world it is just known as varicella. Patients develop a blister-like rash, which first appears on the face and trunk, and then spreads throughout the body.
Modular arithmetic. Time-keeping on a clock gives an example of modular arithmetic. Modular arithmetic, sometimes also called clock arithmetic, is a way of doing arithmetic with integers. Much like hours on a clock, which repeat every twelve hours, once the numbers reach a certain value, called the modulus, they go back to zero. People talked about modular arithmetic in many ancient cultures.
The modern approach to modular arithmetic was developed by Carl Friedrich Gauss in his book Disquisitiones Arithmeticae, published in 1801. A familiar use of modular arithmetic is in the 12-hour clock, in which the day is divided into two 12-hour periods. If the time is 7:00 now, then 8 hours later it will be 3:00.ince modular arithmetic has such a wide range of applications, it is important to know how hard it is to solve a system of congruences. A linear system of congruences can be solved in polynomial time with a form of Gaussian elimination, for details see linear congruence theorem.