For five years, a San Francisco foundation funded, and a research organization closely monitored, a collaboration by 10 California districts to raise achievement under the Common Core math standards.

Although the State Board of Education adopted new Common Core standards in math and English language arts nearly seven years ago, some school districts are still in the process of implementing them.

Most of the states that first endorsed the Common Core academic standards are still using them in some form, despite continued debate over whether they are improving student performance in reading and ...