# All About Math, In One Place

## Most Popular ### Multiples and Factors

Multiples and Factors Multiples You can think multiples of a number as the” times table” for that number. For example: the multiplies of 3 are:3 × 1 = 3,  3 × 2 = 6,  3 × 3 = 9 and so on. A multiple of a number is found when you multiply that number by a positive integer. The […] ### Powers and Roots

Powers and Roots An expression that represents repeated multiplication of the same factor is called a power. So, when we want to multiply a number by itself repeatedly we use powers. $displaystyle {{a}^{n}}$ tells  you  to multiply  a  by itself, exactly n-times. The exponent corresponds to the number of times the base is used as […] ### Prime and composite numbers

Prime and Composite numbers Prime numbers are numbers that have exactly two factors: one and the number itself. Composite numbers are numbers that have more than two factors. Finding prime numbers Over 2000 years ago, a Greek mathematician called “Eratosthenes” made a simple tool for sorting out prime numbers. This tool is called the “Sieve of Eratosthenes” […] ### Finding the length of a straight line

Finding the length of a straight line What is a straight line? A straight line is the set of all points between and extending two points. In most geometries, a line is a primitive object that does not have formal properties beyond length, its single dimension. The two properties of a straight line in Euclidian […] ### Box-and-whisker plots 