Simple Java Math Problem Generator Runs and Terminates

My program is supposed to ask the user a multiplication problem. If the user answers correctly, it prints "Great job! Here is another problem: [insert problem]" (it never stops doing this). If the user answers incorrectly, the program says "Not quite. Try again: [same problem]" until the user answers correctly. It asks the first question, and the user answers correctly, but it does not display the message it should. It displays the message the second time the user gets a correct answer. The third time the user gets the answer correct, it terminates. Thankfully, the user keeps repeating the same question indefinitely (program will not move on from the same question until user is correct). Here is the code:

import java.security.SecureRandom;
import java.util.Scanner;

public class MethodMath {
    static int num1; // Holds actual secure random number
    static int num2; // Holds another actual secure random number
    static SecureRandom number1; // Becomes a new instance of secureRandom
    static SecureRandom number2; // Becomes another new instance of secureRandom
    static int answer; // Becomes user input
    private static Scanner input = new Scanner(System.in);// Creates new scanner

    MethodMath() {  } // Constructor

    public void isFalse() {
        while (num1 * num2 != answer) { // Asks same question until user gets it right
            System.out.print("Not quite. Try again: What is " + num1 + " times " + num2 + "?: ");
            answer = input.nextInt();
        }
    }

    public boolean numGen() { // Generates multiplication problems ()
        number1 = new SecureRandom();
        num1 = number1.nextInt(10);

        number2 = new SecureRandom();
        num2 = number2.nextInt(10);

        System.out.print("What is " + num1 + " times " + num2 + "?: ");
        answer = input.nextInt();
        this.isFalse();
        return true;
    }

    public static void main(String[] args) {
        MethodMath mm = new MethodMath();

        // Computer assisted instruction program
        mm.numGen(); // First problem
        if (mm.numGen()) { // If numGen returns true
            System.out.println("Great job! Here is another problem: ");
            mm.numGen();
        }
    }
}

Why is it terminating after 3 correct answers?

It's terminating after 3 correct answers, because you only call mm.numGen(); 3 times. I think what you want as a main-Method is:

public static void main(String[] args) {
MethodMath mm = new MethodMath();
while(mm.numGen()) {
System.out.println("Great job! Here is another problem: ");
}
}

If you want to keep on asking questions, change:

if (mm.numGen()) {// If numGen returns true
System.out.println("Great job! Here is another problem: ");
mm.numGen();}

to:

while (mm.numGen()) {// If numGen returns true
System.out.println("Great job! Here is another problem: ");}

Explanation:

While the condition in the brackets is true (in this case your numGen returns true), the code will continue executing

Try setting the program up in a true OOP fashion. The better a program flows, the easier it is to read.

Pass the scanner to the class for better resource handling. I am not sure why you created multiple instances of SecureRandom, as one will work just as well. Also, the program will exit it a non-numeric value is submitted.

import java.security.SecureRandom;
import java.util.InputMismatchException;
import java.util.Scanner;

public class MethodMath {
    private Scanner input;
    private SecureRandom rand;

    public MethodMath(Scanner input) {
        this.input = input;
        this.rand = new SecureRandom();
    }

    public void start() {
        do {
            try {
                numGen();
                System.out.println("Great job! Here is another problem:\n");
            } catch (InputMismatchException e) {
                break;
            }
        } while (true);

        System.out.println("Now exiting...");
    }

    protected void checkAnswer(int num1, int num2) {
        boolean correct = false;
        int answer = num1 * num2;

        do {
            System.out.printf("What is %d times %d?: ", num1, num2);
            int response = input.nextInt();

            if (response == answer) {
                input.nextLine(); // Flush the buffer.
                correct = true;
                break;
            }
            System.out.print("Not quite. Try again: ");
        } while (!correct);
    }

    protected void numGen() { // Generates multiplication problems ()
        int num1 = rand.nextInt(10);
        int num2 = rand.nextInt(10);
        checkAnswer(num1, num2);
    }

    public static void main(String[] args) {
        Scanner input = new Scanner(System.in); // Creates new scanner
        MethodMath mm = new MethodMath(input);

        mm.start(); // Computer assisted instruction program

        input.close();
    }
}

Here is an example of a generic prompt that can ask the user a random multiplication or addition problem.

import java.security.SecureRandom;
import java.util.*;

public abstract class MethodMath {
    private Scanner input;
    private SecureRandom rand;
    private int max;

    public static final class Multiplication extends MethodMath {
        public Multiplication(Scanner input, int max) {
            super(input, max);
        }

        @Override
        public int calculate(int a, int b) {
            return a * b;
        }

        @Override
        public String prompt(int a, int b) {
            return String.format("What is %d times %d?: ", a, b);
        }
    }

    public static final class Addition extends MethodMath {
        public Addition(Scanner input, int max) {
            super(input, max);
        }

        @Override
        public int calculate(int a, int b) {
            return a + b;
        }

        @Override
        public String prompt(int a, int b) {
            return String.format("What is %d plus %d?: ", a, b);
        }
    }

    public MethodMath(Scanner input, int max) {
        this.input = input;
        this.rand = new SecureRandom();
        this.max = max;
    }

    public abstract int calculate(int a, int b);

    public abstract String prompt(int a, int b);

    protected void solve() {
        int num1 = rand.nextInt(this.max);
        int num2 = rand.nextInt(this.max);
        boolean correct = false;
        int answer = calculate(num1, num2);
        do {
            System.out.print(prompt(num1, num2));
            int response = input.nextInt();
            if (response == answer) {
                input.nextLine(); // Flush the buffer.
                correct = true;
                break;
            }
            System.out.print("Not quite. Try again: ");
        } while (!correct);
    }

    public static void main(String[] args) {
        Random r = new Random(System.currentTimeMillis());
        Scanner input = new Scanner(System.in);

        List<MethodMath> prompts = new ArrayList<>(Arrays.asList(
            new Multiplication(input, 4),
            new Addition(input, 10)
        ));

        do {
            try {
                int randIndex = r.nextInt(prompts.size());
                MethodMath prompt = prompts.get(randIndex);
                prompt.solve();
                System.out.println("Great job! Here is another problem:\n");
            } catch (InputMismatchException e) {
                break;
            }
        } while (true);

        System.out.println("Now exiting...");

        input.close();
    }
}