diff --git a/lib/binary_to_decimal.rb b/lib/binary_to_decimal.rb
index 439e8c6..6990847 100644
--- a/lib/binary_to_decimal.rb
+++ b/lib/binary_to_decimal.rb
@@ -1,9 +1,18 @@
-# A method named `binary_to_decimal` that receives as input an array of size 8.
+# A method named `binary_to_decimal` that
+#receives as input an array of size 8.
 # The array is randomly filled with 0’s and 1’s.
 # The most significant bit is at index 0.
 # The least significant bit is at index 7.
-# Calculate  and return the decimal value for this binary number using
+# Calculate  and return the decimal value for
+# this binary number using
 # the algorithm you devised in class.
+
 def binary_to_decimal(binary_array)
-  raise NotImplementedError
+  index = binary_array.length - 1
+  result = 0
+  while index >= 0
+    result += binary_array[index] * (2 ** (7 - index))
+    index -= 1
+  end
+  return result
 end