You should store the numbers in a list, and use a loop to add numbers to it.
import numpy
size = int(input("Enter number of numbers you would like to enter"))
numbers = []
for i in range(size):
numbers.append(int(input("Please type in number %d" % i)))
median = numpy.median(numbers)
print(median)
Your approach fails because you try to use numbers as variable names, which is not valid.