Greta Heinke and Kenneth Cisneros, both in transitional kindergarten, play a memory match game together during free choice time at Bishop School in Sunnyvale Elementary District. (Photo by Liv Ames)

As a result of a new state law, California schools instituted transitional kindergarten to give 4-year-olds who were previously eligible for kindergarten an extra year to adjust to school and experience a less academically-oriented curriculum. But many thousands of those children are in classrooms with kindergartners, leaving teachers to figure out how to accommodate the new approach for 4-year-olds while preparing the 5-year-olds for 1st grade.

In 2013-14, about 57,000 students were estimated to have been in transitional kindergarten, and 78 percent of the classes were combination classes with both kindergartners and transitional kindergartners, according to the most recent data provided by the California Department of Education. An estimated 1,298 classes were stand-alone transitional kindergarten, while 4,674 were mixed classes.

California used to allow all students who turned 5 by Dec. 2 to enter kindergarten. But beginning in 2012-13, legislators pushed back the entry date for kindergarten and phased in transitional kindergarten for the youngest students, reaching full implementation this school year. To be eligible for transitional kindergarten, children must turn 5 between Sept. 2 and Dec. 2.

Legislators and early education advocates expected some mixed classes, because in many schools there are not enough transitional kindergartners to form a separate class.

Read the full story on EdSource.