0-9减法/循环计算五道减法题/10道加法题

单次计算

import java.util.*;
class Main {
  public static void main(String []args) {
    //1. Generate two random single-digit integers
    int number1 = (int)(Math.random() * 10);
    int number2 = (int)(Math.random() * 10);

    //2. If number1 < number2, swap number1 with number2
    if(number1 < number2){
      int temp = number1;
      number1 = number2;
      number2 = temp;
    }

    //3. Prompt the student to answer "What is number1 - number2?"
    System.out.print("What is " + number1 +" - " + number2 + "?");
    Scanner input = new Scanner(System.in);
    int answer = input.nextInt();

    //4. Grade the answer and display the result
    if(number1 - number2 == answer){
      System.out.println("Your answer is correct!");
    }else{
      System.out.println("Your answer is wrong\n" + number1 + " - " 
                        + number2 + "should be " + (number1-number2));
    }
  } 
 
}

循环计算五道题

import java.util.*;
class Main {
  public static void main(String []args) {
    final int NUMBER_OF_QUESTIONS = 5;//Number of questions
    int correctCount = 0;//Coutn the number of correct answers
    int count = 0;//Count the number of questions
    long startTime = System.currentTimeMillis();
    String output = "";//output string is initially empty
    Scanner input = new Scanner(System.in);

    while(count < NUMBER_OF_QUESTIONS){
      //1. Generate two random single-digit integers
      int number1 = (int)(Math.random() * 10);
      int number2 = (int)(Math.random() * 10);
      
      //2. If number1 < number2, swap number1 with number2
      if(number1 < number2){
        int temp = number1;
        number1 = number2;
        number2 = temp;
      }
      
      //3. Prompt the student to answer "What is number1 - number2?"
      System.out.print("What is " + number1 +" - " + number2 + "? ");  
      int answer = input.nextInt();
      
      //4. Grade the answer and display the result
      if(number1 - number2 == answer){
        System.out.println("Your answer is correct!");
        correctCount++;
      }else{
        System.out.println("Your answer is wrong\n" + number1 + " - " 
                        + number2 + " should be " + (number1-number2));
      }

      //Increase the count
      count++;
      output += "\n" + number1 + "-" + number2 + " = " + answer +
        ((number1 - number2 == answer) ? " correct" : " wrong");
    }

    long endTime = System.currentTimeMillis();
    long testTime = endTime - startTime;
    System.out.println("\nCorrect count is " + correctCount + 
                       "\nWrong count is " + (NUMBER_OF_QUESTIONS - correctCount) +
                      "\nTest time is " + testTime / 1000 + " seconds\n" + output);
  } 
  
}

计算10道加法题

import java.util.*;
class Main {
  public static void main(String []args) {
    final int NUMBER_OF_QUESTIONS = 10;//Number of questions
    int correctCount = 0;//Coutn the number of correct answers
    long startTime = System.currentTimeMillis();
    String output = "";//output string is initially empty
    Scanner input = new Scanner(System.in);

    for(int count = 0; count < NUMBER_OF_QUESTIONS;count++){
      //1. Generate two random single-digit integers
      int number1 = (int)(Math.random() * 100) % 15 + 1;
      int number2 = (int)(Math.random() * 10) % 15 + 1;
     
      //2. Prompt the student to answer "What is number1 + number2?"
      System.out.print("What is " + number1 +" + " + number2 + "? ");  
      int answer = input.nextInt();

      //3. Grade the answer and display the result
      if(number1 + number2 == answer){
        System.out.println("Your answer is correct!");
        correctCount++;
      }else{
        System.out.println("Your answer is wrong\n" + number1 + " + " 
                        + number2 + " should be " + (number1+number2));
      }

      output += "\n" + number1 + " + " + number2 + " = " + answer +
        ((number1 + number2 == answer) ? " correct" : " wrong");
    }

    long endTime = System.currentTimeMillis();
    long testTime = endTime - startTime;
    System.out.println("\nCorrect count is " + correctCount + 
                       "\nWrong count is " + (NUMBER_OF_QUESTIONS - correctCount) +
                      "\nTest time is " + testTime / 1000 + " seconds\n" + output);
  } 
  
}