【加强版】小学数学出题，加减乘除混合运算，支持自定义数字，一键打印

在线预览：在线HTML代码预览和运行工具 - UU在线工具复制下面代码后到该地址预览即可

注意：在线预览不能打印。如需打印，在电脑本地上新建文本文档，粘贴代码后保存，然后把文件后缀改为.html运行，出题点击打印就可以了

新增功能：
1、支持加减乘除运算混合多选
2、支持自定义数字运算个数
3、支持自定义出题数量
4、支持一键打印成pdf
5、小学数学没有负数，保证结果不出现负数
6、出题分列展示、新增答案下划线
7、界面美化

<!DOCTYPE html>
<html lang="zh">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>小学生数学题生成器</title>
    <style>
        body {
            font-family: Arial, sans-serif;
            background-color: #f4f4f4;
            margin: 0;
            display: block;
            flex-direction: column;
            align-items: center;
            justify-content: center;
        }
        #options {
            display: block;
            margin: 20px auto;
            background-color: #fff;
            border-radius: 5px;
            box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
            padding: 20px;
            box-sizing: border-box;
            width: 500px;
			line-height: 35px;
        }

        label {
            margin-right: 10px;
            margin-bottom: 10px;
            font-size: 16px;
        }

        button {
    padding: 5px;
    background-color: #4caf50;
    color: #fff;
    border: none;
    border-radius: 5px;
    cursor: pointer;
        }

        #questions {
            display: flex;
            flex-wrap: wrap;
            justify-content: space-between;
            margin-top: 20px;
        }

        .question {
            width: 48%;
            box-sizing: border-box;
            padding: 10px;
            background-color: #fff;
            border-radius: 5px;
            box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
            margin-bottom: 10px;
            font-size: 18px;
        }

        .answer {
            display: none;
            font-size: 16px;
        }

        #printHeader {
            display: none;
            margin-bottom: 20px;
        }

        @media print {
            #printHeader {
                display: block;
                text-align: center;
                margin-bottom: 30px; 
            }

            body {
                margin: 30px; 
            }

            .column {
                display: inline-block;
                width: 48%;
                box-sizing: border-box;
                margin-bottom: 20px;
                break-before: auto; 
            }

            .question {
                page-break-inside: avoid; 
            }

            @page {
                size: A4;
                margin: 25mm 10mm 25mm 10mm;
            }

            .question:nth-child(n+21) {
                display: none;
            }
        }
		div#printHeader {
    text-align: center;
    margin-bottom: 15px;
}
    </style>
</head>
<body>
    <div class="hd1" style="text-align:center;font-size:35px;background-color: #4CAF50;min-height: 100px;padding-top: 50px;"><font>小学生数学题生成器</font></div>
    <div id="options">运算符号：
        <label>
            <input type="checkbox" id="additionCheckbox" checked="checked"> 加法
        </label>
        <label>
            <input type="checkbox" id="subtractionCheckbox"> 减法
        </label>
        <label>
            <input type="checkbox" id="multiplicationCheckbox"> 乘法
        </label>
        <label>
            <input type="checkbox" id="divisionCheckbox"> 除法
        </label>
        <br>
        <label>
            数字个数：<input type="number" id="numOfDigits" value="2" min="1" style="width: 50px;">
        </label> <br>
        <label>
            允许小数：<input type="checkbox" id="allowDecimal">
        </label>
        <br>
        <label>
            数字范围：
            <label><input type="number" id="minRange" value="1" min="1" style="width: 50px;"></label>-
            <label><input type="number" id="maxRange" value="100" min="1" style="width: 50px;"></label>
        </label>
        <br>
        <label>
            出题数量：<input type="number" id="numOfQuestions" value="30" min="1" style="width: 50px;">
        </label>
        <br>
        <button onclick="generateQuestions()">生成题目</button>
        <button onclick="printQuestions()">一键打印</button>
        <button onclick="toggleAnswers()">显示/隐藏答案</button>
    </div>

    <div id="questions"></div>

    <script>

		function generateQuestions() {
            const addition = document.getElementById("additionCheckbox").checked;
            const subtraction = document.getElementById("subtractionCheckbox").checked;
            const multiplication = document.getElementById("multiplicationCheckbox").checked;
            const division = document.getElementById("divisionCheckbox").checked;
            const numOfDigits = document.getElementById("numOfDigits").value;
            const allowDecimal = document.getElementById("allowDecimal").checked;
            const minRange = parseInt(document.getElementById("minRange").value);
            const maxRange = parseInt(document.getElementById("maxRange").value);
            const numOfQuestions = document.getElementById("numOfQuestions").value;

            const questionsContainer = document.getElementById("questions");
            questionsContainer.innerHTML = "";

            for (let i = 0; i < numOfQuestions; i++) {
                let validQuestion = false;
                let questionText, answerText;

                while (!validQuestion) {
                    const operators = getRandomOperators(addition, subtraction, multiplication, division, numOfDigits);
                    const numbers = generateNumbers(numOfDigits, allowDecimal, minRange, maxRange);
                    questionText = generateQuestionText(numbers, operators, allowDecimal);
                    answerText = calculateAnswer(numbers, operators, allowDecimal).toFixed(allowDecimal ? 2 : 0);

                    if (!containsNegativeNumber(questionText) && answerText >= 0) {
                        validQuestion = true;
                    }
                }

                const questionDiv = document.createElement("div");
                questionDiv.classList.add("question");

                questionDiv.innerHTML = `<span>${questionText}</span><span class="answer">${parseFloat(answerText)}</.toFixed(2)}</span>`;
                questionsContainer.appendChild(questionDiv);
            }
        }

        function getRandomOperators(addition, subtraction, multiplication, division, numOfDigits) {
            const availableOperators = [];
            if (addition) availableOperators.push('+');
            if (subtraction) availableOperators.push('-');
            if (multiplication && numOfDigits >= 2) availableOperators.push('*');
            if (division && numOfDigits >= 2) availableOperators.push('/');

            const selectedOperators = [];
            for (let i = 0; i < numOfDigits - 1; i++) {
                const randomOperator = availableOperators[Math.floor(Math.random() * availableOperators.length)];
                selectedOperators.push(randomOperator);
            }

            return selectedOperators;
        }

        function generateQuestionText(numbers, operators, allowDecimal) {
            let questionText = numbers[0].toString();
            for (let i = 0; i < operators.length; i++) {
                const operator = operators[i];
                const num = allowDecimal ? parseFloat(numbers[i + 1]).toFixed(2) : parseInt(numbers[i + 1]);
                questionText += ` ${operator.replace('*', 'x').replace('/', '÷')} ${num}`;
            }
            questionText += ' =';

            return questionText;
        }

        function generateNumbers(numOfDigits, allowDecimal, minRange, maxRange) {
            const randomNumber = () => allowDecimal 
                ? (Math.random() * (maxRange - minRange) + minRange).toFixed(2)
                : Math.floor(Math.random() * (maxRange - minRange + 1)) + minRange;

            const numbers = [];
            for (let i = 0; i < numOfDigits; i++) {
                numbers.push(randomNumber());
            }
            return numbers;
        }

        function calculateAnswer(numbers, operators, allowDecimal) {
            const calculateMulDiv = (nums, ops) => {
                for (let i = 0; i < ops.length; i++) {
                    if (ops[i] === '*' || ops[i] === '/') {
                        const result = ops[i] === '*' ? nums[i] * nums[i + 1] : nums[i] / nums[i + 1];
                        nums.splice(i, 2, result);
                        ops.splice(i, 1);
                        i--;
                    }
                }
            };

            const nums = numbers.map(num => parseFloat(num));
            const ops = operators.map(op => op);

            calculateMulDiv(nums, ops);

            let result = nums[0];
            for (let i = 0; i < ops.length; i++) {
                const num = nums[i + 1];
                const operator = ops[i];

                switch (operator) {
                    case '+':
                        result += num;
                        break;
                    case '-':
                        result -= num;
                        break;
                    default:
                        break;
                }
            }

            return allowDecimal
                ? parseFloat(result.toFixed(2))
                : parseInt(result);
        }

        function containsNegativeNumber(questionText) {
            const parts = questionText.split(' ');
            for (let i = 0; i < parts.length; i++) {
                if (parseFloat(parts[i]) < 0) {
                    return true;
                }
            }
            return false;
        }

        function printQuestions() {
            const printWindow = window.open('', '_blank');
            const printContent = document.getElementById("questions").innerHTML;

            printWindow.document.write(`
                <html lang="zh">
                <head>
                    <meta charset="UTF-8">
                    <meta name="viewport" content="width=device-width, initial-scale=1.0">
                    <title>打印题目</title>
                    <style>
                        body {
                            font-family: Arial, sans-serif;
                            margin: 30px; 
                        }

                        .column {
                            display: inline-block;
                            width: 48%;
                            box-sizing: border-box;
                            margin-bottom: 20px;
                        }

                        .question {
                            padding: 10px;
                            background-color: #fff;
                            border-radius: 5px;
                            box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
                            margin-bottom: 10px;
                            font-size: 18px;
                        }

                        .answer {
                            display: none;
                            font-size: 16px;
                        }
                    </style>
                </head>
                <body>
                    <div id="printHeader" style="text-align: center;margin-bottom: 20px;">
                        <div>姓名：_________ 日期：____月____日 时间：________ 答对：_______题</div>
                    </div>
                    <div class="column" id="column1"></div>
                    <div class="column" id="column2"></div>
                </body>
                </html>
            `);

            const column1 = printWindow.document.getElementById("column1");
            const column2 = printWindow.document.getElementById("column2");
            const questions = document.querySelectorAll('.question');

            let countColumn1 = 0;
            let countColumn2 = 0;

            questions.forEach((question, index) => {
                const column = index % 2 === 0 ? column1 : column2;
                const clonedQuestion = question.cloneNode(true);

                // Replace answer content with formatted answer
                const answerElement = clonedQuestion.querySelector('.answer');
                const answerText = answerElement.textContent;
                answerElement.textContent = parseFloat(answerText).toFixed(2);

                column.appendChild(clonedQuestion);

                if (index % 2 === 0) {
                    countColumn1++;
                } else {
                    countColumn2++;
                }
            });

            printWindow.document.close();
            printWindow.print();
        }

        function toggleAnswers() {
            const answers = document.querySelectorAll('.answer');
            answers.forEach(answer => {
                answer.style.display = (answer.style.display === 'none' || answer.style.display === '') ? 'inline' : 'none';
            });
        }
		
		
    </script>
</body>
</html>