Search results
Results from the WOW.Com Content Network
Casting out nine hundred ninety nines is done by adding groups of three digits. Since 37·27 = 999, = So we can use the remainder from casting out nine hundred ninety nines to get the remainder of division by thirty seven.
Casting out nines is a quick way of testing the calculations of sums, differences, products, and quotients of integers in decimal, a method known as long ago as the 12th century. [3] If an odd perfect number exists, it will have at least nine distinct prime factors. [4] Non-intersecting chords between four points on a circle
For example, in base 10, the digit sum ... For divisibility by 9, this test is called the rule of nines and is the basis of the casting out nines technique for ...
Casting out nines makes use of the fact that if + =, then (() + ()) = (). In the process of casting out nines, both sides of the latter equation are computed, and if they are not equal, the original addition must have been faulty.
The method of casting out nines offers a quick check of decimal arithmetic computations performed by hand. It is based on modular arithmetic modulo 9, and specifically on the crucial property that 10 ≡ 1 (mod 9).
Long division is the standard algorithm used for pen-and-paper division of multi-digit numbers expressed in decimal notation. It shifts gradually from the left to the right end of the dividend, subtracting the largest possible multiple of the divisor (at the digit level) at each stage; the multiples then become the digits of the quotient, and the final difference is then the remainder.
Second method example 1050 → 0501 (reverse) → 0×1 + 5×3 + 0×2 + 1×6 = 0 + 15 + 0 + 6 = 21 (multiply and add). ANSWER: 1050 is divisible by 7. Vedic method of divisibility by osculation Divisibility by seven can be tested by multiplication by the Ekhādika. Convert the divisor seven to the nines family by multiplying by seven. 7×7=49.
Main page; Contents; Current events; Random article; About Wikipedia; Contact us