Math Enrichment Summer Institute
Math Enrichment is a WASC Accredited independent summer program for students entering grades K-11. There are numerous sites in the San Jose, CA area. The programs are just over a month long, and run from 9am-3pm. Depending on the site, students take half a day of language arts and half a day of math (most sites) or a full day of math. The cost is $960 in 2014 for most sites.
You can find out more at www.mathenrichment.net/x/