Switched to command-line-argument input.

sum/src/main/java/edu/unl/cse/soft160/sum/Sum.java

@@ -4,12 +4,12 @@ import java.util.Scanner;
 
 public class Sum {
 	public static void main(String[] args) {
-		Scanner scanner = new Scanner(System.in);
-		System.out.print("Enter a number: ");
-		double firstNumber = scanner.nextDouble();
-		System.out.print("Enter another number: ");
-		double secondNumber = scanner.nextDouble();
-		scanner.close();
+		Scanner firstScanner = new Scanner(args[0]);
+		double firstNumber = firstScanner.nextDouble();
+		firstScanner.close();
+		Scanner secondScanner = new Scanner(args[1]);
+		double secondNumber = secondScanner.nextDouble();
+		secondScanner.close();
 		double sum = firstNumber + secondNumber;
 		System.out.println("The sum is " + sum + ".");
 	}