Common Core is huge around our house lately as Austin's school just started using it and we have to keep up with it. I think this book will be very helpful in making sure I have stuff to help challenge Austin when there are days with no homework or times he wants something to do for school.
It is filled with English and Math worksheets and everything you need to meet Common Core Standards. It is a great resource for teachers and even for homeschoolers!
You can download a sample-- Click Here