I, of course being the crafty woman I am, made the comment I can make this and for once actually did!
Here's a quick word tute with no follow along pictures because it is really simple and straight forward to make:
-1 wood plaque or round wood peice (I found mine at Michaels fairly cheap and most craft or hobby stores sell them)
-Paint and brushes (you can pick any colors you want but make sure you can see the numbers from across the room. As for brushes I used a sponge brush for the black)
-Clock parts (another thing I got at Michaels. You can also reuse an old clock)
-Your math ( I copied the one from the website after the boy had to spend a few minutes number crunching in his head)
You might need to drill a hole in your wood before going any futher. Find your center and grab an electric drill and some borbits. I had to enlarge the hole several times before the peices would go through and depending on your clock guts you will too.
Paint the wood the base color of your choice. This one of course being black. You might need more then one coat so let dry between each coat and don't forget to do the sides!
Mark your 12 o'clock position on the clock. To do this fit the base and peg through the hole you made and hold it like it was hanging on the wall. More then likely your clock face will start to rotate a little and then stop. Because its hard to get exactly center on the wood gravity is going to center it for you. Mark the top with eithier you number or a small mark.
Here's where a little bit of tricky comes in. At this point you want to attach the hour and minute hands to the clock peice. Set the clock to 12 and then trace on the back how your clock base is set. With most clock bases they won't stay attached to the clock unless you nail or glue them there. I nailed mine in and how you get it to stay is up to you. The marks on the back are just a guide to make sure you have some idea how it should be.
How to place the hours correctly is to keep the hands on the face and start setting each hour and marking where it should go. I made a line from the tip on the hour hand to the edge of the clock for each hour.
Remove the hands once you have all the hours labeled and start to put in the actual math problems. Start with 12, 3, 9, 6 so that you can get the general idea of spacing. Always keep 12 at the top or your writing will start to slant.
Let dry and put on the hands. You can seal the paint if you would like but I like the matte finish on my boys. Put in the battery and make sure everything is ticking correctly.
I liked making this one so much I plan on making a couple more. I am going to do a periodic table for myself and I was planing on a kitchen conversion chart for my kitchen.
As for the math, it is correct. If you do plan on checking the math like my boytoy did then you will find 7 o'clock can actually be 6, 7, or -6. We proved the other night we are a bunch of math geeks because he and I got into an argument about the answer.
If you have any questions or ideas drop me a line of course and I'll answer or ponder them.