Answer:
import java.util.Scanner;
class Main {
public static int calcSeries(int n) {
int sum = 0;
for(int i=10; i>=n; i--) {
sum += i;
}
return sum;
}
public static void main(String[] args) {
Scanner reader = new Scanner(System.in);
int n = 0;
do {
System.out.print("Enter n: ");
n = reader.nextInt();
if (n >= 10) {
System.out.println("Please enter a value lower than 10.");
}
} while (n >= 10);
reader.close();
System.out.printf("sum: %d\\", calcSeries(n));
}
}