diff --git a/maths/power_of_two.rb b/maths/power_of_two.rb
index 5d514be..2eb24a8 100644
--- a/maths/power_of_two.rb
+++ b/maths/power_of_two.rb
@@ -119,6 +119,11 @@ puts is_power_of_two(n)
 # Approach 4: Bitwise operators: Turn off the Rightmost 1-bit
 # 
 
+# Note that there are two ways of solving this problem via bitwise operations:
+# 1. How to get / isolate the rightmost 1-bit: x & (-x).
+# 2. How to turn off (= set to 0) the rightmost 1-bit: x & (x - 1).
+# In this approach, we're reproducing item 2.
+
 # Complexity Analysis
 # 
 # Time complexity: O(1).