Spelling Ring Toss
Here is a great game that you can make, then play, with your grandkids.  You will need the following items:

18 X 24 piece of plywood or heavy cardboard
ruler
marker
28 cup hooks
clothes line
masking tape

How To
Using your ruler or yardstick, divide the plywood into 3 sections across the top (short side) and 6 sections along the side (long side).  Draw lines so that you have a total of 18 boxes.  At the corner of each box, screw in a cup hook.  Print a letter of the alphabet under each of the hooks, leaving two hooks blank (any two are fine).

Make rings out of clothes line by cutting sections about 8 inches long and then forming a loop and securing it with a piece of masking tape.

To play the game, choose a short word and take turns trying to "spell" out that word by hooking the needed letters.  The two blank hooks will be penalty hooks and result in no letters gained.  The first one to spell the word wins.