Donna’s answer is direct: hold on, Mom and Dad. The SAT is designed for high-school juniors, and middle-school students have not yet been taught much of the content.
CTG advises against buying a middle-school student an SAT-prep book. Introducing the test too early may discourage the student and turn the SAT into an object of dread or fear.
A better foundation
Read for pleasure
Encourage the student to read something - anything - that genuinely appeals to them. Fluency, comprehension and a positive relationship with reading are strong long-term foundations.
Do math for fun
Protect the student’s ability to reason through a problem using logic and problem-solving skills. Donna recommends working through enjoyable contest-style problems together.
Donna specifically recommends Math Olympiad Contest Problems for Elementary and Middle Schools by George Lenchner as a source of problems to work through with a parent.
Keep curiosity intact
Middle school is often when math anxiety begins. Enjoyable problem-solving at home can help students remain confident and willing to think through unfamiliar questions.