diff --git a/script.js b/script.js
new file mode 100644
index 0000000..464ee03
--- /dev/null
+++ b/script.js
@@ -0,0 +1,88 @@
+let displayValue = '0';  // 显示屏上的内容
+let firstNumber = null;  // 第一个数字
+let secondNumber = null; // 第二个数字
+let operation = null;    // 运算符
+let waitingForSecondNumber = false;
+
+// 更新显示
+function updateDisplay() {
+    const display = document.getElementById('display');
+    display.innerText = displayValue;
+}
+
+// 添加数字
+function appendNumber(number) {
+    if (waitingForSecondNumber) {
+        displayValue = number.toString();
+        waitingForSecondNumber = false;
+    } else {
+        displayValue = displayValue === '0' ? number.toString() : displayValue + number.toString();
+    }
+    updateDisplay();
+}
+
+// 设置运算符
+function setOperation(op) {
+    if (firstNumber === null) {
+        firstNumber = parseFloat(displayValue);
+    } else if (operation) {
+        secondNumber = parseFloat(displayValue);
+        firstNumber = performCalculation(firstNumber, secondNumber, operation);
+        displayValue = firstNumber.toString();
+        updateDisplay();
+    }
+    operation = op;
+    waitingForSecondNumber = true;
+}
+
+// 计算结果
+function calculate() {
+    if (operation && !waitingForSecondNumber) {
+        secondNumber = parseFloat(displayValue);
+        displayValue = performCalculation(firstNumber, secondNumber, operation).toString();
+        firstNumber = null;
+        secondNumber = null;
+        operation = null;
+        updateDisplay();
+    }
+}
+
+// 执行计算
+function performCalculation(num1, num2, operator) {
+    switch (operator) {
+        case '+':
+            return num1 + num2;
+        case '-':
+            return num1 - num2;
+        case '*':
+            return num1 * num2;
+        case '/':
+            return num2 !== 0 ? num1 / num2 : '错误';
+        default:
+            return num2;
+    }
+}
+
+// 百分号处理
+function percent() {
+    displayValue = (parseFloat(displayValue) / 100).toString();
+    updateDisplay();
+}
+
+// 添加小数点
+function appendSymbol(symbol) {
+    if (!displayValue.includes(symbol)) {
+        displayValue += symbol;
+        updateDisplay();
+    }
+}
+
+// 清除显示
+function clearDisplay() {
+    displayValue = '0';
+    firstNumber = null;
+    secondNumber = null;
+    operation = null;
+    waitingForSecondNumber = false;
+    updateDisplay();
+}