diff --git a/csharp/Platform.Numbers.Tests/MathTests.cs b/csharp/Platform.Numbers.Tests/MathTests.cs
new file mode 100644
index 0000000..79934b9
--- /dev/null
+++ b/csharp/Platform.Numbers.Tests/MathTests.cs
@@ -0,0 +1,49 @@
+using Xunit;
+
+namespace Platform.Numbers.Tests
+{
+    public static class MathTests
+    {
+        [Fact]
+        public static void AbsTest()
+        {
+            // Test with signed integers
+            Assert.Equal(5, Math<int>.Abs(-5));
+            Assert.Equal(5, Math<int>.Abs(5));
+            Assert.Equal(0, Math<int>.Abs(0));
+            
+            // Test with long
+            Assert.Equal(123L, Math<long>.Abs(-123L));
+            Assert.Equal(123L, Math<long>.Abs(123L));
+            
+            // Test with double
+            Assert.Equal(3.14, Math<double>.Abs(-3.14));
+            Assert.Equal(3.14, Math<double>.Abs(3.14));
+            
+            // Test with unsigned types (should return same value)
+            Assert.Equal(42u, Math<uint>.Abs(42u));
+            Assert.Equal(0u, Math<uint>.Abs(0u));
+        }
+
+        [Fact]
+        public static void NegateTest()
+        {
+            // Test with signed integers
+            Assert.Equal(-5, Math<int>.Negate(5));
+            Assert.Equal(5, Math<int>.Negate(-5));
+            Assert.Equal(0, Math<int>.Negate(0));
+            
+            // Test with long
+            Assert.Equal(-123L, Math<long>.Negate(123L));
+            Assert.Equal(123L, Math<long>.Negate(-123L));
+            
+            // Test with double
+            Assert.Equal(-3.14, Math<double>.Negate(3.14));
+            Assert.Equal(3.14, Math<double>.Negate(-3.14));
+            
+            // Test with float
+            Assert.Equal(-2.5f, Math<float>.Negate(2.5f));
+            Assert.Equal(2.5f, Math<float>.Negate(-2.5f));
+        }
+    }
+}
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diff --git a/csharp/Platform.Numbers/Math[T].cs b/csharp/Platform.Numbers/Math[T].cs
new file mode 100644
index 0000000..799fdf2
--- /dev/null
+++ b/csharp/Platform.Numbers/Math[T].cs
@@ -0,0 +1,53 @@
+using System;
+using System.Numerics;
+using System.Runtime.CompilerServices;
+
+namespace Platform.Numbers
+{
+    /// <summary>
+    /// <para>Represents a set of math operations using direct reference to operator methods of .NET classes.</para>
+    /// <para>Представляет набор математических операций, используя прямую ссылку на методы операторов классов .NET.</para>
+    /// </summary>
+    public static class Math<T> where T : INumberBase<T>
+    {
+        /// <summary>
+        /// <para>Returns the absolute value of a number.</para>
+        /// <para>Возвращает абсолютное значение числа.</para>
+        /// </summary>
+        /// <param name="x">The number to get the absolute value of.</param>
+        /// <returns>The absolute value of the input number.</returns>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static T Abs(T x)
+        {
+            if (typeof(T) == typeof(sbyte))
+                return T.CreateTruncating(System.Math.Abs((sbyte)(object)x));
+            if (typeof(T) == typeof(short))
+                return T.CreateTruncating(System.Math.Abs((short)(object)x));
+            if (typeof(T) == typeof(int))
+                return T.CreateTruncating(System.Math.Abs((int)(object)x));
+            if (typeof(T) == typeof(long))
+                return T.CreateTruncating(System.Math.Abs((long)(object)x));
+            if (typeof(T) == typeof(float))
+                return T.CreateTruncating(System.Math.Abs((float)(object)x));
+            if (typeof(T) == typeof(double))
+                return T.CreateTruncating(System.Math.Abs((double)(object)x));
+            if (typeof(T) == typeof(decimal))
+                return T.CreateTruncating(System.Math.Abs((decimal)(object)x));
+
+            // For unsigned types, absolute value is the number itself
+            return x;
+        }
+
+        /// <summary>
+        /// <para>Returns the negation of a number.</para>
+        /// <para>Возвращает отрицание числа.</para>
+        /// </summary>
+        /// <param name="x">The number to negate.</param>
+        /// <returns>The negated value of the input number.</returns>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static T Negate(T x)
+        {
+            return -x;
+        }
+    }
+}
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