"Summer School" prep for next year

Well my two oldest are going to be in first grade so I get to figure out free ways to get them ready, any moms from New York state have any tips since part of curriculum is common core?

NicolePerry, New York
About Nicole
Current: Perry, New York
Birth: May 12
On Moms.com since: Aug 25, 2014
I am a Mommy of two children by birth and one by marriage.