do{                     //Begin of loop
    try{                        //Try this code
        System.out.println("Enter a number");
        double i = read.nextDouble(); //Reads user input
        double rn = r.nextInt(10);   //Generates random number rn
        System.out.println(i +  " divided by random number " + rn + " is " + (i/rn));
    }catch(InputMismatchException type_error){         //Catches error if there is a type mismatch
        //Example error: if user enters a letter instead of a double
         System.out.println("Error. You cannot divide a letter by a number!");
        break;  //break stops the execution of the program
    }

    //using a continue statement here does not work
}while(true);       //Loop forever

Scanner read = new Scanner(System.in);
    Random r = new Random();

    do {                     //Begin of loop

        try {                        //Try this code
            System.out.println("Enter a number");
            double i = read.nextDouble(); //Reads user input
            double rn = r.nextInt(10);   //Generates random number rn
            System.out.println(i + " divided by random number " + rn + " is " + (i / rn));

        } catch (InputMismatchException type_error) {         //Catches error if there is a type mismatch
            //Example error: if user enters a letter instead of a double
            System.out.println("Error. You cannot divide a letter by a number!");

            // Empty the scanner before the next iteration:
            read.next();
        }

    //using a continue statement here does not work
    } while (true);       //Loop forever

Scanner read = new Scanner(System.in);
do {
    try {
        // trimmed out non-necessary stuff
        System.out.println("Enter a number");
        double i = Double.parseDouble(read.nextLine());
        System.out.println(i);
        // changed exception caught
    }
    catch (NumberFormatException type_error) {
        System.out.println("Error. You cannot divide a letter by a number!");
        continue;
    }

} while (true);

do{                     //Begin loop

    try{                        //Try this code
        System.out.println("Enter a number");
        double i = read.nextDouble(); //Reads user input
        double rn = r.nextInt(10);   //Generates random number rn
        System.out.println(i +  " divided by random number " + rn + " is " + (i/rn));


    }catch(InputMismatchException type_error){         //Catches error if there is a type mismatch
    //Example error: if user enters a letter instead of a double
         System.out.println("Error. You cannot divide " + read.next() + " by a number!");

    }



} while(true);