Java Programming: Loops and Conditionals

Laura Brown teaches 3rd grade. She and her students would like a computer program to practice multiplication. Laura would like the students to practice on random multiplication questions based on random numbers between 1 and 10. Laura would also like the student to be able to pick the number of questions that the program will ask.

import java.util.Scanner; import java.util.Random; public class Main {    public static void main(String[] args) {        Scanner input = new Scanner(System.in);        Random rand = new Random();        System.out.print("Enter number of questions you wish to practice: ");        int n = input.nextInt();        int i = 1;        while(i <= n){            int num1 = 1 + rand.nextInt(10);            int num2 = 1 + rand.nextInt(10);            int answer = num1 * num2;            System.out.print("Question " + i + ": " + num1 + " x " + num2 + " = ");            int response = input.nextInt();            if(response == answer){                System.out.println("Correct answer!");            }            else{                System.out.println("Wrong answer. It should be " + answer);            }            i++;        }    } }

Explanation:

Firstly, we import Scanner and Random classes (Line 1-2) as we need to get user input for number of questions and generate random number in each question.

Next, create a Scanner and Random object (Line 7-8).  Prompt user to input number of question and get the input using the Scanner object (Line 10-11).

Next create a while loop and set the condition to loop for n number of times (based on number of questions) (Line 14). In the loop, use Random object nextInt method to generate two integers between 1 -10 (Line 15-16). Prompt user to input an answer using the Scanner object (Line 18-19). If the response is matched with answer print a correct message (Line 21-22) other wise inform user they write a wrong answer and show the correct answer (Line 24-25).