There are a lot of online sites that offer math worksheets for third graders. One good one is www.homeschoolmath.net/worksheets/grade_3.php This one seems helpful.
Try looking online! Look up "5th grade math worksheets", and go from there! Or ask your local school if they have an extra workbook you can have. I'm sure they'd be happy to help!
There are many free grammar worksheets online at grammaracy dot com. They offer the worksheets for free allowing you to download or save or print them while you are on their site.
Here is a link which will provide you with several online locations to find some free context worksheets to teach reading skills to children: http://www.readingprograms.info/readingresources.html
First go to http://www.ereadingworksheets.com/free-reading-worksheets/reading-comprehension-worksheets/inferences-worksheets/. There you should find multiple links as to what you are looking for.
There are many places online where you can find free addition worksheets, and also customize them for your child. For example, http://www.homeschoolmath.net/worksheets/addition.php and http://www.mathsisfun.com/worksheets/addition.php.
The website www.homeschoolmath.net has many worksheets that can be printed to assist with teaching children how to count money. These worksheets are free to print.
There are a number of places online which offer free algebra worksheets. Math Drills and Math Worksheets Go have free algebra worksheets available. Other places which offer free algebra worksheets include Helping With Math and Soft Schools.
The website www.havefunteaching.com/worksheets has many different types of calendar worksheets available to print. These calenders are free and customizable.
You can find science worksheets online at the following sites I found for you to look at. Here are the sites I found for you to look at www.softschools.com/science/ , and www.jumpstart.com
You can find free teacher worksheets online on websites like Education.com, Super Teacher Worksheets, and Teachers Pay Teachers. These sites offer a wide range of printable worksheets for various subjects and grade levels.
www.schoolsparks.com/kindergarten-worksheets is a good place to find worksheets. There are some free worksheets available to download and there is also a workbook of worksheets available for purchase.
I know that school worksheets dot com has some for you to review and checkout. That site allows you to search and download some free capitalization worksheets.