Solution to 2,4,6,8 puzzle

First, if you think that you have solved the puzzle, you can check your solution:

Now, if you didn't get the puzzle completely correct, you can look at a set of steps to get to the correct solution. Keep in mind that there is probably more than one set of correct steps to get to the one correct answer, since at any point any square that you can fill in without guessing is fair game to fill with the number that you figure out without guessing. This time, you have enough experience to fill in the reasoning on your own. Here are the steps:




This work was made possible through a grant from the National Science Foundation.