diff --git a/src/dotnetCampus.OpenXmlUnitConverter/Percentage.cs b/src/dotnetCampus.OpenXmlUnitConverter/Percentage.cs
index 7ffa2f5..b7a3c53 100644
--- a/src/dotnetCampus.OpenXmlUnitConverter/Percentage.cs
+++ b/src/dotnetCampus.OpenXmlUnitConverter/Percentage.cs
@@ -178,7 +178,8 @@ public override int GetHashCode()
         /// <returns></returns>
         public static Percentage operator *(Percentage a, Percentage b)
         {
-            return new Percentage(a.IntValue * b.IntValue);
+            // 相乘 和 相除 都要考虑倍率，不如直接靠 DoubleValue 来计算
+            return FromDouble(a.DoubleValue * b.DoubleValue);
         }
 
         /// <summary>
@@ -191,7 +192,7 @@ public override int GetHashCode()
         {
             if (b.IntValue == 0) throw new DivideByZeroException();
 
-            return new Percentage(a.IntValue / b.IntValue);
+            return FromDouble(a.DoubleValue / b.DoubleValue);
         }
 
         /// <summary>
diff --git a/tests/dotnetCampus.OpenXmlUnitConverter.Tests/PercentageTest.cs b/tests/dotnetCampus.OpenXmlUnitConverter.Tests/PercentageTest.cs
index 46f4fd5..196793e 100644
--- a/tests/dotnetCampus.OpenXmlUnitConverter.Tests/PercentageTest.cs
+++ b/tests/dotnetCampus.OpenXmlUnitConverter.Tests/PercentageTest.cs
@@ -1,4 +1,7 @@
-using Microsoft.VisualStudio.TestTools.UnitTesting;
+using System;
+
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+
 using MSTest.Extensions.Contracts;
 
 namespace dotnetCampus.OpenXmlUnitConverter.Tests
@@ -23,5 +26,17 @@ public void ParsePercentageText()
                 Assert.AreEqual(99999, percentage.IntValue);
             });
         }
+
+        [ContractTestCase]
+        public void TestCalculate()
+        {
+            "非零百分比除以自己等于 100%".Test((double value) =>
+            {
+                var percentage = Percentage.FromDouble(value);
+
+                var result = percentage / percentage;
+                Assert.AreEqual(true, Math.Abs(result.DoubleValue - 1) < 0.000001);
+            }).WithArguments(1.5, 2.3, 3.6, 100.5, 100000.123);
+        }
     }
 }