diff --git a/xiang_mu/mymath.py b/xiang_mu/mymath.py
new file mode 100644
index 0000000..39fe184
--- /dev/null
+++ b/xiang_mu/mymath.py
@@ -0,0 +1,81 @@
+"""
+mymath.py - 数学运算模块
+提供乘法和除法运算
+"""
+
+def multiply(a: float, b: float) -> float:
+    """
+    计算两个数字的乘积
+
+    Args:
+        a: 第一个数字
+        b: 第二个数字
+
+    Returns:
+        两个数字的乘积
+    """
+    return a * b
+
+
+def divide(a: float, b: float) -> float:
+    """
+    计算两个数字的除法
+
+    Args:
+        a: 被除数
+        b: 除数
+
+    Returns:
+        两个数字的商
+
+    Raises:
+        ValueError: 如果除数为零
+    """
+    if b == 0:
+        raise ValueError("除数不能为零")
+    return a / b
+
+
+if __name__ == "__main__":
+    # 测试乘法函数
+    print("测试乘法函数:")
+    test_cases_multiply = [
+        (2, 3, 6),
+        (-4, 5, -20),
+        (0, 7, 0),
+        (2.5, 4, 10.0),
+        (-3.5, -2, 7.0),
+    ]
+
+    for a, b, expected in test_cases_multiply:
+        result = multiply(a, b)
+        status = "PASS" if abs(result - expected) < 1e-9 else "FAIL"
+        print(f"  multiply({a}, {b}) = {result} {status} (期望: {expected})")
+
+    # 测试除法函数
+    print("\n测试除法函数:")
+    test_cases_divide = [
+        (10, 2, 5),
+        (-15, 3, -5),
+        (0, 5, 0),
+        (7.5, 2.5, 3.0),
+        (-9, -3, 3),
+    ]
+
+    for a, b, expected in test_cases_divide:
+        try:
+            result = divide(a, b)
+            status = "PASS" if abs(result - expected) < 1e-9 else "FAIL"
+            print(f"  divide({a}, {b}) = {result} {status} (期望: {expected})")
+        except ValueError as e:
+            print(f"  divide({a}, {b}) 错误: {e}")
+
+    # 测试除数为零的情况
+    print("\n测试除数为零:")
+    try:
+        divide(10, 0)
+        print("  divide(10, 0) FAIL (期望抛出ValueError)")
+    except ValueError as e:
+        print(f"  divide(10, 0) PASS 正确抛出异常: {e}")
+
+    print("\n所有测试完成!")
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