Here’s a good puzzle to get warmed up! This KenKen® grid requires the use of addition and subtraction in order to figure out which number goes in each square. Playing this fun game is a good way to improve logical thinking skills and improve computation. Here's how:

Using the digits 1-4 in this 4x4 puzzle, fill the small squares with digits so as not to repeat a digit in any row or column, and so that the digits within each heavily outlined area will equal that area’s corner number when combined using the indicated operation. For more information visit www.kenken.com. “KenKen® is a registered trademark of Nextoy, LLC, ©2009, KenKen Puzzle LLC”.  All rights reserved.