Where is 100? State the row and column number. 
 
Please check out my YouTube Channel "Math Challenge" for the SOLUTION! SCAN that QR Code to take you right to the video!
 
I would be SUPER DELIGHTED AND HAPPILY EMBARRASSED LOL if you showed my video to your class explaining the solution! 
 
If you LOVE these types of problems, as a beginning YouTuber, 
it would help me out so much if you could SUBSCRIBE TO MY YouTube Channel! 
 
Also I would LOVE to know how the problem worked out for your kiddos :) 
Any requests for future problems is greatly appreciated!
 
THANK YOU SO MUCH!! 
 
E-mail: knishimori@bridgemath.com