Final answer:
The school surveyed 10% of the 7th-grade students, and 8 indicated math as their favorite subject. By multiplying by 10, we estimate that approximately 80 students in the whole grade favor math.
Step-by-step explanation:
The school surveyed 10% of their 7th-grade students, and out of those, 8 students said math is their favorite subject. To estimate the total number of 7th graders who favor math, we scale up the number of math-favoring students to account for the entire population. Since 8 is 10% of the interested group, we can assume that to find the full 100%, we multiply 8 by 10, giving us an estimate of 80 students in total who may favor math.