Our school groups by ability so every classroom teaches at least the state curriculum, but some go further. My son's K class last year was doing addition, subtraction, patterns and numbers to 100. They were also tested on telling time to the hour and half hour and counting money (he had not learned this at home).
All the kids were reading and doing the AR program by the end of the year. They were tested on the Dolch list -- 100 sight words and the kids breezed through it so the teacher gave out the next 100 words. They learned lots of songs and poems. His favorite part was the math competitions they had at the end of the day.
The curriculum was not terribly challenging for my son, but many things were new to him. His reading improved greatly and he started writing little stories. The math moved too slowly so we supplemented with Singapore at home.
