find_primes.rb

# write a function called find_primes, where you pass in an integer (like 100),
# and your function will calculate all the prime numbers from 1 - 100

# https://en.wikipedia.org/wiki/Sieve_of_Eratosthenes

def find_primes(integer)
  current_ary = (2..integer).to_a
  current_idx = 0

  while current_idx < current_ary.length
    current_ary.delete_if do |e|
      current_ary[(current_idx + 1)..-1].member?(e) &&
        e % current_ary[current_idx] == 0
    end
    current_idx += 1
  end

  current_ary
end

find_primes(100)
# puts find_primes(100).inspect

this is very slick -- well done!

Watch your spacing; number%factor should be number % factor