private void lengthConversionsMenu() throws InterruptedException {

    System.out.println();
    println("Choose a conversion or enter any integer to go back:");
    println("0: Centimeters to meters");
    println("1: Meters to centimeters");
    println("2: Microns to centimeters");
    println("3: Centimeters to microns");
    println("4: Nanometers to microns");
    println("5: Microns to nanometers");
    println("6: Picometers to nanometers");
    println("7: Nanometers to picometers");

    switch (input.nextInt()) {

      case 0:
        // Centimeters to meters
        amount();
        double centimeters = input.nextDouble();
        println(Conversions.centimetersToMeters(centimeters) + " m");
        break;

      case 1:
        // Meters to centimeters
        amount();
        double meters = input.nextDouble();
        println(Conversions.metersToCentimeters(meters) + " cm");
        break;

      case 2:
        // Microns to centimeters
        amount();
        double microns = input.nextDouble();
        println(Conversions.micronsToCentimeters(microns) + " cm");
        break;

      case 3:
        // Centimeters to microns
        amount();
        double centimeters1 = input.nextDouble();
        println(Conversions.centimetersToMicrons(centimeters1) + " microns");
        break;

      case 4:
        // Nanometers to microns
        amount();
        double nanometers = input.nextDouble();
        println(Conversions.nanometersToMicrons(nanometers) + " microns");
        break;

      case 5:
        // Microns to nanometers
        amount();
        double microns1 = input.nextDouble();
        println(Conversions.micronsToNanometers(microns1) + " nm");
        break;

      case 6:
        // Picometers to nanometers
        amount();
        double picometers = input.nextDouble();
        println(Conversions.picometersToNanometers(picometers) + " nm");
        break;

      case 7:
        // Nanometers to picometers
        amount();
        double nanometers1 = input.nextDouble();
        println(Conversions.nanometersToPicometers(nanometers1) + " pm");
        break;

      default:
        // Return to conversions menu
        conversionsMenu();
    }

  }