arr = [ {"amount"=>"5000.00"} , {"amount"=>"250.00"}, {"amount"=>"($200.00)"}, {"amount"=>"250.00"}, {"amount"=>"300.00"}, {"amount"=>"1200.00"} ]
arr.map(&:values).flatten.map { |i| i.delete('()$') } # => ["5000.00", "250.00", "200.00", "250.00", "300.00", "1200.00"]