There are several points in grade school that involve a critical shift in the thinking that is required in the school work. Parent's should be aware of these points as they navigate through the abyss of raising a school-aged child and supporting the child as he/she moves forward through the grades.
3rd Grade - The third grader is transitioning from whole number thinking into understanding the concepts of parts. They are exposed to fractions, decimals and percentages. This is a major paradigm shift. Students are also exposed to long division at this point. Supporting children in this phase requires an emphasis on helping the child conceptualize whole things being split into parts. In addition to homework support, tutoring, and supplementary work, parents should introduce cooking chores to children at this time, and make them follow a recipe that has precise measurements. Reading comprehension and writing is also an issue here. 3rd grade is the last year where children are "learning to read," (I'll explain this as I discuss 4th grade), so there is a big push for the 3rd grader to read a passage and recall facts from the passage, and understanding the main idea. Students will spend a lot of time writing, and they will learn to write in cursive (although many schools are moving away from this).
4th Grade - In 4th grade, the student transitions from "learning to read," to "reading to learn." This will be apparent not only in their reading and language arts classes, but also in other classes. Science and social studies classes will have more to read, and mathematics word problems will require more reading comprehension abilities. In mathematics, students will begin performing operations on "the parts" (fractions, decimals, percentages).
6th Grade - The sixth grade is the transitioning from the real time, in-the-moment mathematical thinking of elementary school arithmetic into the "bigger-picture" that is algebra. Integers are introduced at this point. Just as children had to re-adjust for understanding parts of a whole in 3rd grade, the 6th grader will have to adjust to understanding "less than nothing." Essay writing at this point will become more complex and the students will be expected to show deeper thought than exhibited in elementary school. And for the first time, science and social studies will have with their own teachers in different classrooms (although some elementary schools do this beginning in 4th and 5th grade).
9th Grade - The high school freshman year can be an awkward one. Everything is more challenging. Classic novels will be required reading on a monthly or semi-monthly basis. Science labs start to get serious at this point. And Algebra presents a whole different ballgame, where the teenager is exposed to more abstract, bigger-picture mathematical concepts.
All K-12 students could use assistance during the school year, as well as the summer. But these stages are very critical because of the changes that accompany them.