Our son recently grade skipped over fourth to the fifth. He has missed the social studies and science courses for fourth, so I would like to go over both with him to fill any gaps. I asked the fifth grade teacher for the books the fourth grade uses, but they aren't Common Core based so the fourth grade teacher has put together her own curriculum.

I'd like to find something I can use online or in a workbook format.

Has anyone a suggestion?

Here social studies and science are pretty random before high school and it honestly wouldn't matter. Are you sure it does where you are? If so I would just ask for a list of topics and visit the library.

For social studies, I would look for some good books at an appropriate level in the topic areas for him to read, rather than doing workbooks.

In my state, there are specific topics that are covered each year. Your state should have some kind of common core guidelines published somewhere. If you can't find it, ask a fourth grade teacher at your school to tell you. Then go and get books / movies / etc. covering the topics covered in 4th grade. I don't think it matters what the 4th grade teacher is using.

Common core standards can be read online at corestandards.org. Social Studies and Science are found under English Language Arts (ELA) and are termed "literacy" in social studies and science. The content at this link shows that common core standards for social studies and science begin at grade 6 and range through grade 12.

You may wish to look into homeschooling resources, such as those found on Gifted Homeschoolers Forum (GHF). On their website, "Favorite Things" is a great list of resources.

Time 4 Learning offers lessons by grade level for a monthly fee. One might use their list of 4th grade topics as an outline and fill in with materials found independently.

IXL offers lessons by grade level. One might use their list of 4th grade topics as an outline and fill in with materials found independently.

Education.com lists 4th grade lessons and worksheets here.

Spelling City offers 4th grade vocabulary for "States and Regions" here.

Thanks for the wonderful replies. I knew I could count on getting some good advice here.