To find out #8254-:458#, let us first factorize each number #8254# and #458# so that they are product of prime factors.
#8254=2xx4127# and #458=2xx229# as #4127# and #229# are prime numbers.
Hence #8254-:458=(2xx4127)/(2xx229)=4127/229=18 5/229#
Important - It is not easy to identify large prime numbers, except by continuously trying to divide them by prime numbers starting from #2# and use divisibility rules to the extant possible. However, one should try only till near the square root of the number, because if there is no prime number dividing the number then no other prime will divide it.
For example as #sqrt4127=64.24...#, one should try only till #61#, the last prime before #sqrt4127#. For #229#, one could try till #13# (you may try how we got this?).
Another way could be to convert improper fraction into proper fraction and then try to simplify fraction part. In above case, we have got #5/229# and as #229# cannot be divided by #5#, #18 5/229# is what we get.
