error line 11...no implicit conversion of string to integer. what am i doing wrong?

acct.rb

class AccountCheck
	
	def initialize(acct)
		@acct = acct
		@ALL_ACCOUNTS =[1234,5678,9456]
		firstCheck(@acct)
	end
	def addAccount(desiAcct)
		puts "Enter your full name."
		new_name = gets.chomp
		$newAcct = Array.new[desiAcct.to_i, new_name.to_s]
	end
	def getAccount(acct_num)
		@ACCT_ACCOUNTS.each do |acct|
			if acct == acct_num 
				puts "#{acct}"
			end
		end
	end
	def firstCheck(acct_input)
			@ALL_ACCOUNTS.each do |x|
			if acct_input == x 
				puts "Account Found."
				#need to bring up name and account info here LEARN ARRAY IN ARRAY
				getAccount(acct_input)
				
				
			else 
				#option to create a new account
				puts "Not Found...would you like to create one? y/n"
				createNew = gets.chomp
				if createNew == "y"
					puts "Enter your desired Account Number"
					desiAccount = gets.chomp
					addAccount(desiAccount)
				else 
					puts "Come back again"
				end
				
				
			end
			end
	end