Science/Social Studies Assessments

I teach 4th grade and we have our students for the whole day. We don't switch classes or teachers for other subjects. I am finding it hard to teach both Science and Social Studies well to all my students to the point where I feel comfortable enough to give them a test. Those are typically times when Title One support pulls students or Math Core pulls students so they are missing the main lesson. I give them a quick mini lesson when they return but it's not the same. It's also a subject that is hard to differentiate, like you typically do for math and reading. I feel the book tests are too difficult for what little time we have to teach those subjects so I am wondering what do other upper elementary teachers do for assessments in those subject areas when the time is so limited?