I modified it as follows:

package actorobject

import scala.actors._

object Adder extends Actor {

var sum = 0
override def act() = {
react {
case i: Int => sum += i; act()
case “REPORT” => println(“Total =\t” + sum);
}
}
}

object Main {
def main(args: Array[String]): Unit = {
Adder.start
(1 to 10000).foreach( i => if( i % 3 == 0 || i % 5 == 0 ) Adder ! i )
Adder ! “REPORT”
}
}