Now that the boys are in pre-K, we're starting to work on kindergarten readiness such as writing, phonics and simple math concepts. Their preschool is staunchly play-based (and we have no complaints because we feel it's important for them, especially as twins, to develop social skills), so any academic preparation is going to be coming from us. I'm pretty relaxed about the whole thing; it's not like I hold formal classes or anything. They occasionally work on activity books when they feel like it, and when we read books together I sometimes pick out a two or three letter word and help them read it.
We've recently added another tool to our arsenal: Tunza write-on-rub-off index cards. I've been using them to create flashcards for the kids to help the boys read simple words like "cat" and "hat", and for basic addition problems like 3+1 (The Pea also loves it when I write out more complicated math problems for her). They enjoy writing down the answers and erasing everything so I can write out new problems.
These Tunza cards are not just for flashcards -- kids can draw on them and you can write your shopping list on them and I'm sure there are (forgive the pun) Tunza other uses. And because they're reusable, they're earth friendly. Everytime the kids reach for the cards to draw instead of a sheet of paper, we're saving money and trees.
The cards work best with permanent Sharpie markers (just rub with alcohol to remove). But anal parent that I am, I feel nervous about letting my kids loose around the house with permanent markers. I've found that dry-erarse markers work perfectly well, and markings come off with a simple swipe.
Thanks to the folks at Tunza for our sample! The kids are really enjoying it.