diff --git a/X10D.Tests/src/Core/ComparableTests.cs b/X10D.Tests/src/Core/ComparableTests.cs
deleted file mode 100644
index 582ef40..0000000
--- a/X10D.Tests/src/Core/ComparableTests.cs
+++ /dev/null
@@ -1,130 +0,0 @@
-using Microsoft.VisualStudio.TestTools.UnitTesting;
-
-namespace X10D.Tests.Core;
-
-/// <summary>
-///     Tests for <see cref="ComparableExtensions" />.
-/// </summary>
-[TestClass]
-public class ComparableTests
-{
-    /// <summary>
-    ///     Tests <see cref="ComparableExtensions.Between{T1, T2, T3}" />
-    /// </summary>
-    [TestMethod]
-    public void Between()
-    {
-        const int lower = 5;
-        const int upper = 15;
-        const int value = 10;
-
-        Assert.IsTrue(value.Between(lower, upper), "value.Between(lower, upper)");
-        Assert.IsFalse(lower.Between(value, upper), "lower.Between(value, upper)");
-        Assert.IsFalse(upper.Between(lower, value), "upper.Between(lower, value)");
-            
-        Assert.IsTrue(upper.Between(lower, upper, InclusiveOptions.UpperInclusive), "upper.Between(lower, upper, Clusivity.UpperInclusive)");
-        Assert.IsTrue(upper.Between(lower, upper, InclusiveOptions.Inclusive), "upper.Between(lower, upper, Clusivity.Inclusive)");
-        Assert.IsFalse(upper.Between(lower, upper, InclusiveOptions.LowerInclusive), "upper.Between(lower, upper, Clusivity.LowerInclusive)");
-            
-        Assert.IsTrue(lower.Between(lower, upper, InclusiveOptions.LowerInclusive), "lower.Between(lower, upper, Clusivity.LowerInclusive)");
-        Assert.IsTrue(lower.Between(lower, upper, InclusiveOptions.Inclusive), "lower.Between(lower, upper, Clusivity.Inclusive)");
-        Assert.IsFalse(lower.Between(lower, upper, InclusiveOptions.UpperInclusive), "lower.Between(lower, upper, Clusivity.UpperInclusive)");
-    }
-
-    /// <summary>
-    ///     Tests <see cref="ComparableExtensions.Clamp{T}" />
-    /// </summary>
-    [TestMethod]
-    public void Clamp()
-    {
-        const int lower = 5;
-        const int upper = 10;
-        const int value = 15;
-
-        Assert.AreEqual(upper, value.Clamp(lower, upper));
-        Assert.AreEqual(upper, lower.Clamp(upper, value));
-        Assert.AreEqual(upper, upper.Clamp(lower, value));
-    }
-
-    /// <summary>
-    ///     Tests <see cref="ComparableExtensions.GreaterThan{T1, T2}" />
-    /// </summary>
-    [TestMethod]
-    public void GreaterThan()
-    {
-        const int first = 5;
-        const int second = 10;
-
-        Assert.IsTrue(second.GreaterThan(first));
-        Assert.IsFalse(first.GreaterThan(second));
-    }
-
-    /// <summary>
-    ///     Tests <see cref="ComparableExtensions.GreaterThanOrEqualTo{T1, T2}" />
-    /// </summary>
-    [TestMethod]
-    public void GreaterThanOrEqualTo()
-    {
-        const int first = 5;
-        const int second = 10;
-
-        Assert.IsTrue(second.GreaterThanOrEqualTo(first));
-        Assert.IsTrue(second.GreaterThanOrEqualTo(second));
-        Assert.IsTrue(first.GreaterThanOrEqualTo(first));
-        Assert.IsFalse(first.GreaterThanOrEqualTo(second));
-    }
-
-    /// <summary>
-    ///     Tests <see cref="ComparableExtensions.GreaterThan{T1, T2}" />
-    /// </summary>
-    [TestMethod]
-    public void LessThan()
-    {
-        const int first = 5;
-        const int second = 10;
-
-        Assert.IsTrue(first.LessThan(second));
-        Assert.IsFalse(second.LessThan(first));
-    }
-
-    /// <summary>
-    ///     Tests <see cref="ComparableExtensions.LessThanOrEqualTo{T1, T2}" />
-    /// </summary>
-    [TestMethod]
-    public void LessThanOrEqualTo()
-    {
-        const int first = 5;
-        const int second = 10;
-
-        Assert.IsTrue(first.LessThanOrEqualTo(second));
-        Assert.IsTrue(first.LessThanOrEqualTo(first));
-        Assert.IsTrue(second.LessThanOrEqualTo(second));
-        Assert.IsFalse(second.LessThanOrEqualTo(first));
-    }
-
-    /// <summary>
-    ///     Tests <see cref="ComparableExtensions.Max{T}" />
-    /// </summary>
-    [TestMethod]
-    public void Max()
-    {
-        const int first = 5;
-        const int second = 10;
-
-        Assert.AreEqual(second, first.Max(second));
-        Assert.AreEqual(second, second.Max(first));
-    }
-
-    /// <summary>
-    ///     Tests <see cref="ComparableExtensions.Min{T}" />
-    /// </summary>
-    [TestMethod]
-    public void Min()
-    {
-        const int first = 5;
-        const int second = 10;
-
-        Assert.AreEqual(first, first.Min(second));
-        Assert.AreEqual(first, second.Min(first));
-    }
-}
\ No newline at end of file
diff --git a/X10D.Tests/src/Math/ComparableTests.cs b/X10D.Tests/src/Math/ComparableTests.cs
new file mode 100644
index 0000000..dd71c7d
--- /dev/null
+++ b/X10D.Tests/src/Math/ComparableTests.cs
@@ -0,0 +1,201 @@
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using X10D.Math;
+
+namespace X10D.Tests.Math;
+
+[TestClass]
+public class ComparableTests
+{
+    private class ComparableTestClass : IComparable<ComparableTestClass>
+    {
+        public int CompareTo(ComparableTestClass? other)
+        {
+            return 0;
+        }
+    }
+
+    private readonly int _lower = 1;
+    private readonly int _upper = 10;
+    private readonly int _value = 5;
+
+    [TestMethod]
+    public void Between_5_1_10_ShouldBeTrue()
+    {
+        Assert.IsTrue(_value.Between(_lower, _upper));
+    }
+
+    [TestMethod]
+    public void Between_1_1_10_ShouldBeFalse()
+    {
+        // default option is exclusive
+        Assert.IsFalse(_lower.Between(_lower, _upper));
+    }
+
+    [TestMethod]
+    public void Between_1_1_10_Inclusive_ShouldBeTrue()
+    {
+        Assert.IsTrue(_lower.Between(_lower, _upper, InclusiveOptions.Inclusive));
+        Assert.IsTrue(_lower.Between(_lower, _upper, InclusiveOptions.LowerInclusive));
+        Assert.IsFalse(_lower.Between(_lower, _upper, InclusiveOptions.UpperInclusive));
+    }
+
+    [TestMethod]
+    public void Between_10_1_10_ShouldBeFalse()
+    {
+        // default option is exclusive
+        Assert.IsFalse(_upper.Between(_lower, _upper));
+    }
+
+    [TestMethod]
+    public void Between_10_1_10_Inclusive_ShouldBeTrue()
+    {
+        Assert.IsTrue(_upper.Between(_lower, _upper, InclusiveOptions.Inclusive));
+        Assert.IsTrue(_upper.Between(_lower, _upper, InclusiveOptions.UpperInclusive));
+        Assert.IsFalse(_upper.Between(_lower, _upper, InclusiveOptions.LowerInclusive));
+    }
+
+    [TestMethod]
+    public void Between_1_10_5_ShouldThrow()
+    {
+        Assert.ThrowsException<ArgumentException>(() => _lower.Between(_upper, _value));
+    }
+
+    [TestMethod]
+    public void Between_Null_ShouldThrow()
+    {
+        ComparableTestClass? nullPointer = null;
+        Assert.ThrowsException<ArgumentNullException>(() => ((ComparableTestClass?)null)!.Between(nullPointer!, nullPointer!));
+    }
+
+    [TestMethod]
+    public void Clamp_3_1_5_ShouldBe3()
+    {
+        Assert.AreEqual(3, 3.Clamp(1, 5));
+    }
+
+    [TestMethod]
+    public void Clamp_10_1_5_ShouldBe5()
+    {
+        Assert.AreEqual(5, 10.Clamp(1, 5));
+    }
+
+    [TestMethod]
+    public void Clamp_n_6_5_ShouldThrow()
+    {
+        Assert.ThrowsException<ArgumentException>(() => 0.Clamp(6, 5));
+    }
+
+    [TestMethod]
+    public void GreaterThan_5_6_ShouldBeFalse()
+    {
+        Assert.IsFalse(5.GreaterThan(6));
+    }
+
+    [TestMethod]
+    public void GreaterThan_6_5_ShouldBeTrue()
+    {
+        Assert.IsTrue(6.GreaterThan(5));
+    }
+
+    [TestMethod]
+    public void GreaterThan_5_5_ShouldBeFalse()
+    {
+        Assert.IsFalse(5.LessThan(5));
+    }
+
+    [TestMethod]
+    public void GreaterThan_Null_ShouldThrow()
+    {
+        ComparableTestClass? nullPointer = null;
+        Assert.ThrowsException<ArgumentNullException>(() => nullPointer!.GreaterThan(nullPointer!));
+    }
+
+    [TestMethod]
+    public void GreaterThanOrEqualTo_5_5_ShouldBeTrue()
+    {
+        Assert.IsTrue(5.GreaterThanOrEqualTo(5));
+    }
+
+    [TestMethod]
+    public void GreaterThanOrEqualTo_6_5_ShouldBeTrue()
+    {
+        Assert.IsTrue(6.GreaterThanOrEqualTo(5));
+    }
+
+    [TestMethod]
+    public void GreaterThanOrEqualTo_5_6_ShouldBeFalse()
+    {
+        Assert.IsFalse(5.GreaterThanOrEqualTo(6));
+    }
+
+    [TestMethod]
+    public void GreaterThanOrEqualTo_Null_ShouldThrow()
+    {
+        ComparableTestClass? nullPointer = null;
+        Assert.ThrowsException<ArgumentNullException>(() => nullPointer!.GreaterThanOrEqualTo(nullPointer!));
+    }
+
+    [TestMethod]
+    public void LessThan_Null_ShouldThrow()
+    {
+        ComparableTestClass? nullPointer = null;
+        Assert.ThrowsException<ArgumentNullException>(() => nullPointer!.LessThan(nullPointer!));
+    }
+
+    [TestMethod]
+    public void LessThan_6_5_ShouldBeFalse()
+    {
+        Assert.IsFalse(6.LessThan(5));
+    }
+
+    [TestMethod]
+    public void LessThan_5_6_ShouldBeTrue()
+    {
+        Assert.IsTrue(5.LessThan(6));
+    }
+
+    [TestMethod]
+    public void LessThan_5_5_ShouldBeFalse()
+    {
+        Assert.IsFalse(5.LessThan(5));
+    }
+
+    [TestMethod]
+    public void LessThanOrEqualTo_5_5_ShouldBeTrue()
+    {
+        Assert.IsTrue(5.LessThanOrEqualTo(5));
+    }
+
+    [TestMethod]
+    public void LessThanOrEqualTo_5_6_ShouldBeTrue()
+    {
+        Assert.IsTrue(5.LessThanOrEqualTo(6));
+    }
+
+    [TestMethod]
+    public void LessThanOrEqualTo_6_5_ShouldBeFalse()
+    {
+        Assert.IsFalse(6.LessThanOrEqualTo(5));
+    }
+
+    [TestMethod]
+    public void LessThanOrEqualTo_Null_ShouldThrow()
+    {
+        ComparableTestClass? nullPointer = null;
+        Assert.ThrowsException<ArgumentNullException>(() => nullPointer!.LessThanOrEqualTo(nullPointer!));
+    }
+
+    [TestMethod]
+    public void Max_Null_ShouldThrow()
+    {
+        ComparableTestClass? nullPointer = null;
+        Assert.ThrowsException<ArgumentNullException>(() => nullPointer!.Max(nullPointer!));
+    }
+
+    [TestMethod]
+    public void Min_Null_ShouldThrow()
+    {
+        ComparableTestClass? nullPointer = null;
+        Assert.ThrowsException<ArgumentNullException>(() => nullPointer!.Min(nullPointer!));
+    }
+}
diff --git a/X10D/src/ComparableExtensions/ComparableExtensions.cs b/X10D/src/Math/ComparableExtensions.cs
similarity index 99%
rename from X10D/src/ComparableExtensions/ComparableExtensions.cs
rename to X10D/src/Math/ComparableExtensions.cs
index cc12eb2..a382ba4 100644
--- a/X10D/src/ComparableExtensions/ComparableExtensions.cs
+++ b/X10D/src/Math/ComparableExtensions.cs
@@ -1,6 +1,6 @@
 using System.Globalization;
 
-namespace X10D;
+namespace X10D.Math;
 
 /// <summary>
 ///     Extension methods for <see cref="IComparable{T}" />.
diff --git a/X10D/src/ComparableExtensions/InclusiveOptions.cs b/X10D/src/Math/InclusiveOptions.cs
similarity index 93%
rename from X10D/src/ComparableExtensions/InclusiveOptions.cs
rename to X10D/src/Math/InclusiveOptions.cs
index 9c00810..1c78197 100644
--- a/X10D/src/ComparableExtensions/InclusiveOptions.cs
+++ b/X10D/src/Math/InclusiveOptions.cs
@@ -1,7 +1,7 @@
-namespace X10D;
+namespace X10D.Math;
 
 /// <summary>
-///     Provides options for <see cref="ComparableExtensions.Between{T1, T2, T3}" /> clusivity.
+///     Provides options for <see cref="ComparableExtensions.Between{T1,T2,T3}" /> clusivity.
 /// </summary>
 [Flags]
 public enum InclusiveOptions : byte