for-loop console input digital sum and average

Performance statistics three classes, each class of five students, each student achievement own input, calculated the average score average in each class and all classes?

var sum=0
for(j <- 1 until(4)){
  println("请输入第"+j+"个班级的成绩")
  var sum1=0
  for(a <- 1 until(6)){
    println("请输入第"+a+"名同学的分数:")
    var score=readInt()
    sum1+=score
  }
  println(j+"班的五名同学总分数是："+sum1)
  sum+=sum1
}
println("所有三个班级的平均分是："+sum/3)