PRIME FACTORISATION is a method used to find all the prime factors (numbers that are only divisible by one and itself) of a given number.
The method used below is a tree branch method in which the given number 2800, is divided by the lowest possible prime factor (in this case two). This prim factor (divisor) is then placed on a branch that subtends from the original number (in this case the left branch) and on another branch (the right branch) the quotient of this division was written. This was done repeatedly to the quotient (essentially the quotient acted as a dividend each time, continually being divided by the lowest possible prime factor) until no further division was possible (this occurs when the quotient obtained yield one as the quotient after being divided by itself).