For a school probably c-rods for math. I think when my kids were 3 I just help them count their snacks, cheeze-it, etc. Then at the age of 4, adding one or two.
For LA, I'D imagine just reading to them and a trip to story time would be sufficient. How about five in a row curriculum? I try doing some stuff from it with my kids who are 5 1/2 and 4.
Hth.