A few times a week William works through a problem from the book below. I copy it into a blank sketch book so it gives him more space for the drawing.
I had this from my previous teaching days. It includes 45 problems for each grade level. There are also books just for each grade level that include 180 problems.
I used these daily in my classroom and the kids always loved them.
William enjoys working through them. He is almost finished with the kindergarten ones; like I said we only do a few each week. (Plus, we are holding back the academics and encouraging play for a bit longer.)
Each level works through numbers in a variety of ways; such as addition, subtraction, multiplication, division, patterning, shapes, common attributes, fractions and more. It also starts with very basic reading skills and increases in difficulty.
It lets him be creative and gets him thinking about the different ways a problem can be solved.