When someone asks you to add 48 + 27, what happens in your head?

213 Replies

Interesting.  I was at 50 + 25 before I knew why. 

Slowing down I see I did the big stuff and tended to the details later.  Like life!

Originally posted by @Cameron Hunt :

@Jim K. Would you use days for 17 and 57?

No, it wouldn't occur to me to use hours or days. If that first number of the first equation weren't 48...I'm pretty sure hours-in-the-day wouldn't have been my shortcut tool.

17+57  would be 20+60=80, 80-6=74 for me. A much more standard quick-calculation approach. I would NEVER do 15+55=70, 70+4=74. Working off the ten multiples here, like @Dennis Wayne and @Andrew Bounds.


You ever try to explain to a non-US woodworker why half of 3/8ths of an inch is 3/16ths of an inch, and have him insist on trying to measure out 3/8 in. IN FRONT OF YOU as 0.9525 cm and half of that as 0.4765 cm? This is what this exercise feels like.

Free eBook from BiggerPockets!

Ultimate Beginner's Guide Book Cover

Join BiggerPockets and get The Ultimate Beginner's Guide to Real Estate Investing for FREE - read by more than 100,000 people - AND get exclusive real estate investing tips, tricks and techniques delivered straight to your inbox twice weekly!

  • Actionable advice for getting started,
  • Discover the 10 Most Lucrative Real Estate Niches,
  • Learn how to get started with or without money,
  • Explore Real-Life Strategies for Building Wealth,
  • And a LOT more.

We hate spam just as much as you