Browse Teasers
Search Teasers

## Two Digit Numbers

Math brain teasers require computations to solve.

 Puzzle ID: #5101 Fun: (2.22) Difficulty: (2.22) Category: Math Submitted By: mad-ade Corrected By: boodler

Take the 2-digit number 45.
Square it (45 x 45) to make 2025
Split this 4-digit number in half to make 20 and 25
Add them (20 + 25) to make 45
Which is what you started with.
Can you find another 2-digit number which does the same?

55 or 99
Hide

## What Next?

See another brain teaser just like this one...

Or, just get a random brain teaser

If you become a registered user you can vote on this brain teaser, keep track of
which ones you have seen, and even make your own.

 Piffle Jul 09, 2002 This is a good one, I think. Good job. peppermintwist Jul 09, 2002 Clever! george1978 Jul 12, 2002 i liked this one rufio Aug 21, 2002 "Can you find another 2-digit number which does the same?" The correct answer, in my case, was "No." TECHNICALLY, it was the right answer. Smithy Aug 20, 2003 d'oh. Rufio - I was gonna say that. You beat me to it by about a year. Except I was gonna say yes. lessthanjake789 Oct 14, 2006 no one has commented in just about forever on this teaser. clever and tough. id be surprised if you figured that out all on your own, unless you have a system for it. id be interested to hear it actually. if its just a fact then - now i know, and thanks! Jimbo May 11, 2009 It's easily done with a spreadsheet but if you try it algebraically, it is hard to deal with the bit where you split the number in half. This step has a fraction in it which can be removed in a spreadsheet by the 'Round Down' function but it is much more difficult to deal with the remainder in Algebra. I believe that teasers like this belong in the 'Trivia' category unless you accept that creating a spreadsheet is a legitimate way to solve Mathematical teasers. c0forerunner0 Feb 18, 2013 How about 10? Take the 2-digit number 10. Square it to make 100 Split this number to make 10 and 0 Add them to make 10 Which is what you started with. spikethru4 Feb 18, 2013 Well, if you split 100 according to the rules, you'd end up with 01 and 00, which sums to 1, so no.