Installing a robe hook in the middle of a door? Where's the center of a 1-foot, 5-inch board? Finding the exact center of things can be tricky especially where fractions are involved -- like 3/8ths of an inch. However, it can be easy if you know a few tricks of the trade like this one: From deep within the Carey Brothers' vault of how to center a measurement, we bring "middle" management. Using a tape measure, hold the tip end on one side and stretch it straight across to the other side. Let's say it's a door 27 and 5/16ths wide. To find the exact center, hold the tip end in place and swing the other end slightly up (or down) until the edge reads an even number -- say 30 inches. Half of that would be dead center -- here 15 inches. Any even number measure will do 36 inches, 38 inches, 40 inches -- it doesn't matter. Half the even number you choose is always dead center. That's "middle" management. For more tips, visit our Web site at onthehouse.com. And that's the On The House tip for today.