Many online math games are designed purely for entertainment and won't do much in terms of teaching your child. While these games can be fun and engaging for third graders, you want to choose games that will practice the skills being taught in school.
If your child is used to doing a worksheet or two, they will be able to do this quite easily, and will understand that they need to complete the task before they can move on to the next activity. Worksheets also help your child to learn how to follow instructions, and teach them about following rules.
Textbooks, instruction manuals, and lesson plans are the basic foundation for any homeschooling program. Homeschooling does not have to be limited to the parents understanding of the material that the student is learning. Home school information and education should instead be based on the student's individual learning style and the materials that must be taught based on the students grade level and educational needs.
Lacing activities, stringing beads and cheerios, playing with playdoh, scooping sand or rice, and activities like pouring and stirring are also great fine motor activities.