Tell us about yourself!
Yes. Maybe I'm missing something... but your very first number in the exampleis 52. Step #2 says divide by 2. Which would be 26. You have it as 27. Then you multiplied by 10 giving you 270, which is incorrect. Your system works, you just divided incorrectly in the example.
Multiply or Divide Any Number by 5 Fast
Bye the way, 5x52 is 260 but good trick anyway.