3. In a school from I to VIII grade, there is only one class per grade. In grades I-IV, there are a total of 130 students. In grade V, there are 7 more students than in grade II, in grade VI, there are 5 fewer students than in grade I, in grade VII, there are 10 more students than in grade IV, and in grade VIII, there are 4 fewer students than in grade I. How many students are there in grades I-VIII in total?
3. Since there are 8 more students in grades V-VIII than in grades I-IV $(7-5+10-4=8)$, there are a total of 138 students in grades V-VIII ( $130+8=138$ ), and a total of 268 students in grades I-VIII $(130+138=268)$.