Like I mentioned in my post, we don't use a curriculum or even worksheets. (Both girls love their "puzzle books" offered by Highlights magazine however. They are expensive but we enjoy them very, very much.) We do have an alphabet puzzle. Alphabet-oriented books can be fun (Dr. Seuss' ABC, Chicka Chicka..., and Ogres Ogres Ogres, but we get them because they are fun. Mainly we read a lot, about nearly everything.
Math at this age is mainly about counting, and I just can't stop them from counting. We also play a lot of board games together, some "educational", others not, but all are useful, either because of counting dice, money, or graphs (Battleship). Baking provides familiarity with measuring cups. I don't make a point of "teaching" her the measurements, but simply use the vocabulary. My 5yo especially loves her jigsaw puzzles and wooden "picture" blocks. Those are just the wooden shape blocks which they lay out on the yoga mats so they don't slip. Those are a great intuitive way to learn about shapes and their relationship to each other, even if you don't teach the names or the names simply don't "stick".
For science, well that's easy. We just explore. If they ask and I can answer, then I do, but exploring and wondering is the name of the game. I give them some tools to play with, binoculars, measuring tape, etc, and let them loose. And of course, more books-- hopefully in something of a story format, but they have enjoyed the "science" books as well, if they are done nicely and worth reading simply for their own sake. My 5yo loves her guide books. She'll pore over them for hours, telling herself little stories as she goes (though she doesn't want me to hear!) Last bath time my oldest (almost 7yo) discovered that a wet washcloth held tightly over a yogurt tub full of water will hold in the water. No one asked why. I'm still researching that myself. It's the wonder and the thrill of the discovery (on their very own!) that I value. Pure joy! And lots of giggles....