UNIX HELP

I have file (Numbers.txt) that has a list of numbers randomly ranging from 1-300. I wanted to get rid of numbers 120 through 130 strictly through writing a unix script. I thought that the easiest way to do this would be to SORT the numbers in the file (using unix), then write a file containing all numbers before 120 and another file containing all numbers after 130 and combine them. I have no idea how to do that in unix since im so new to the syntax. Someone please help.