diff --git a/lib/binary_to_decimal.rb b/lib/binary_to_decimal.rb
index 439e8c6..2139e1a 100644
--- a/lib/binary_to_decimal.rb
+++ b/lib/binary_to_decimal.rb
@@ -4,6 +4,15 @@
 # The least significant bit is at index 7.
 # 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
+  exponent_array = [2**7, 2**6, 2**5, 2**4, 2**3, 2**2, 2**1, 2**0]
+  result_array = []
+  index = 0
+  while result_array.length < binary_array.length
+    (binary_array[index]).zero? ? num_to_add = 0 : num_to_add = binary_array[index] * exponent_array[index]
+    result_array << num_to_add
+    index += 1
+  end
+  result_array.sum
 end