definitions
Operation Of Real Numbers
Properties of addition on R :
Closure Property : The sum of two real numbers is always a real number. We say that R is closed for addition. …
Multiplication By Short Cut-Methods
Multiplication of a Number By 99, 999, 9999 etc. : Place as many zeros to the right of the multiplicand as is the number of nines and from the number so formed, subtract the multiplicand to get the answer.
e.g. Multiplyi…
Tests for Divisibility
Divisible by 2n : If last n digits of a number is divisible by 2n, the whole number is divisible by 2n.
Divisible by 2 : A number is divis…