Solving KenKen Logic Puzzles

Like its SuDoku cousin, the KenKen grid (Fig. #1) has squares that must be filled with numbers that can not repeat in any row or column. The size of the grid determines the numbers that must be filled. A 4 x 4 grid uses 1 through 4, a 6 x 6 grid 1 through 6, etc. However, unlike SuDoku, instead of blocks KenKen logic puzzles contain various groups of boxes called "cages" and in the upper left-hand corner of each cage is a target number and a mathematical sign indicating how the numerals within a particular cage interact to produce the target number. (Please note! A number may repeat within a cage as long as it does not repeat in any row or column.) For this tutorial we'll begin with an easy 4x4 grid with 8 "cages". We have to fill the squares with the numbers 1 through 4 so that no number repeats in any row or column (just as in a SuDoku puzzle) while meeting the target number of each "cage".