Division without fractions

Q: I read in one of your issues a while back about dividing a distance into equal parts: For example, how can I divide a tall bookshelf into equally spaced shelves? The method was very simple and easy, all done with a measuring tape. Can you help me?

A: Associate editor Daniel S. Morrison replies: This method works best dividing wide chunks of wood, so for bookcases, you’ll need to determine the shelf heights on a wide sheet before you rip the plywood into bookcase sides. Let’s say you want to divide a 68-in. bookcase into six equal shelves. Choose some number bigger than 68 in. that divides evenly into six, such as 72. Hook your tape at one end of the plywood and stretch it diagonally across the plywood until 72 intersects the 68-in. mark. Mark the divisors 12, 24, 36, 48, and 60. Presto! Equal spaces, no math