diff --git a/Upsilon/BaseTypes/Number/ScriptNumber.cs b/Upsilon/BaseTypes/Number/ScriptNumber.cs
index 7d8924a..6a6400a 100644
--- a/Upsilon/BaseTypes/Number/ScriptNumber.cs
+++ b/Upsilon/BaseTypes/Number/ScriptNumber.cs
@@ -2,9 +2,9 @@ using System;
 
 namespace Upsilon.BaseTypes.Number
 {
-    internal abstract class ScriptNumber : ScriptType
+    public abstract class ScriptNumber : ScriptType
     {
-        protected abstract bool IsFloat { get; }
+        protected internal abstract bool IsFloat { get; }
 
         public override Type Type => Type.Number;
 
diff --git a/Upsilon/BaseTypes/Number/ScriptNumberDouble.cs b/Upsilon/BaseTypes/Number/ScriptNumberDouble.cs
index f64eac9..693230b 100644
--- a/Upsilon/BaseTypes/Number/ScriptNumberDouble.cs
+++ b/Upsilon/BaseTypes/Number/ScriptNumberDouble.cs
@@ -5,7 +5,7 @@ namespace Upsilon.BaseTypes.Number
     internal class ScriptNumberDouble : ScriptNumber
     {
         public double Value { get; }
-        protected override bool IsFloat { get; } = true;
+        protected internal override bool IsFloat { get; } = true;
 
         public ScriptNumberDouble(double value)
         {
diff --git a/Upsilon/BaseTypes/Number/ScriptNumberLong.cs b/Upsilon/BaseTypes/Number/ScriptNumberLong.cs
index ca766ed..b6bd156 100644
--- a/Upsilon/BaseTypes/Number/ScriptNumberLong.cs
+++ b/Upsilon/BaseTypes/Number/ScriptNumberLong.cs
@@ -6,7 +6,7 @@ namespace Upsilon.BaseTypes.Number
     internal class ScriptNumberLong : ScriptNumber
     {
         public long Value { get; set; }
-        protected override bool IsFloat { get; } = false;
+        protected internal override bool IsFloat { get; } = false;
 
         public ScriptNumberLong(long val)
         {
diff --git a/Upsilon/BaseTypes/ScriptBoolean.cs b/Upsilon/BaseTypes/ScriptBoolean.cs
index 72731df..ecce633 100644
--- a/Upsilon/BaseTypes/ScriptBoolean.cs
+++ b/Upsilon/BaseTypes/ScriptBoolean.cs
@@ -1,6 +1,6 @@
 namespace Upsilon.BaseTypes
 {
-    internal class ScriptBoolean : ScriptType
+    public class ScriptBoolean : ScriptType
     {
         public ScriptBoolean(bool value)
         {
diff --git a/Upsilon/BaseTypes/ScriptFunction/ScriptMethodInfoFunction.cs b/Upsilon/BaseTypes/ScriptFunction/ScriptMethodInfoFunction.cs
index dc8039a..041f7ef 100644
--- a/Upsilon/BaseTypes/ScriptFunction/ScriptMethodInfoFunction.cs
+++ b/Upsilon/BaseTypes/ScriptFunction/ScriptMethodInfoFunction.cs
@@ -19,6 +19,15 @@ namespace Upsilon.BaseTypes.ScriptFunction
             _passScopeReference = passScopeReference;
 
             ReturnType              = _method.ReturnType;
+
+            if (method.GetMethods().First().Attribute != null)
+            {
+                var attr = method.GetMethods().First().Attribute;
+                _directTypeManipulation = attr.DirectScriptManipulation;
+                _passScriptReference    = attr.PassScriptReference;
+                _passScopeReference     = attr.PassScopeReference;
+
+            }
         }
 
         private readonly UserDataMethod _method;
diff --git a/Upsilon/BaseTypes/UserData/GenericUserData.cs b/Upsilon/BaseTypes/UserData/GenericUserData.cs
index 3930fb9..bda6b39 100644
--- a/Upsilon/BaseTypes/UserData/GenericUserData.cs
+++ b/Upsilon/BaseTypes/UserData/GenericUserData.cs
@@ -3,7 +3,7 @@ using Upsilon.Text;
 
 namespace Upsilon.BaseTypes.UserData
 {
-    internal class GenericUserData : ScriptType, IUserData
+    internal sealed class GenericUserData : ScriptType, IUserData
     {
         public GenericUserData(object dictionary)
         {
@@ -12,7 +12,7 @@ namespace Upsilon.BaseTypes.UserData
         }
         public override Type Type => Type.UserData;
 
-        protected virtual object Value { get; }
+        private object Value { get; }
         private readonly UserDataType _typeInfo;
 
         public override object ToCSharpObject()
@@ -25,7 +25,7 @@ namespace Upsilon.BaseTypes.UserData
             return Value.GetType();
         }
 
-        public virtual ScriptType Get(Diagnostics diagnostics, TextSpan span, ScriptType index, EvaluationScope scope)
+        public ScriptType Get(Diagnostics diagnostics, TextSpan span, ScriptType index, EvaluationScope scope)
         {
             var s = index.ToCSharpObject().ToString();
             var (type, failed, error) = _typeInfo.Get(Value, s);
@@ -36,7 +36,7 @@ namespace Upsilon.BaseTypes.UserData
             return type;
         }
 
-        public virtual void Set(Diagnostics diagnostics, TextSpan span, ScriptType index, ScriptType value)
+        public void Set(Diagnostics diagnostics, TextSpan span, ScriptType index, ScriptType value)
         {
             var s = index.ToCSharpObject().ToString();
             var (failed, error) = _typeInfo.Set(Value, s, value);
diff --git a/Upsilon/BaseTypes/UserData/UserDataMethod.cs b/Upsilon/BaseTypes/UserData/UserDataMethod.cs
index fcb864a..30443dd 100644
--- a/Upsilon/BaseTypes/UserData/UserDataMethod.cs
+++ b/Upsilon/BaseTypes/UserData/UserDataMethod.cs
@@ -2,6 +2,7 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Reflection;
 using Upsilon.Evaluator;
+using Upsilon.StandardLibraries;
 
 namespace Upsilon.BaseTypes.UserData
 {
@@ -13,6 +14,8 @@ namespace Upsilon.BaseTypes.UserData
             {
                 Method = method;
                 var pars = method.GetParameters();
+                Attribute = (ScriptFunctionAttribute) method.GetCustomAttribute(typeof(ScriptFunctionAttribute));
+
                 var ls = new List<UserDataMethodParameter>();
                 foreach (var parameter in pars)
                 {
@@ -26,6 +29,7 @@ namespace Upsilon.BaseTypes.UserData
             }
 
             public MethodInfo Method { get; }
+            public ScriptFunctionAttribute Attribute { get; }
             public UserDataMethodParameter[] Parameters { get; }
         }
 
diff --git a/Upsilon/BaseTypes/UserData/UserDataType.cs b/Upsilon/BaseTypes/UserData/UserDataType.cs
index 0ff22e7..4e010bd 100644
--- a/Upsilon/BaseTypes/UserData/UserDataType.cs
+++ b/Upsilon/BaseTypes/UserData/UserDataType.cs
@@ -2,6 +2,7 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Reflection;
 using Upsilon.BaseTypes.ScriptFunction;
+using Upsilon.StandardLibraries;
 
 namespace Upsilon.BaseTypes.UserData
 {
@@ -16,6 +17,12 @@ namespace Upsilon.BaseTypes.UserData
             foreach (var methodInfo in type.GetMethods())
             {
                 var commonName = methodInfo.Name.ToLowerInvariant();
+                var attribute = methodInfo.GetCustomAttribute(typeof(ScriptFunctionAttribute));
+                if (attribute is ScriptFunctionAttribute sfa )
+                {
+                    commonName = sfa.Name.ToLowerInvariant();
+                }
+
                 if (Methods.TryGetValue(commonName, out var methodData))
                 {
                     methodData.LoadMethodPart(methodInfo);
diff --git a/Upsilon/BoundTypes/UserDataBoundTypeDefinition.cs b/Upsilon/BoundTypes/UserDataBoundTypeDefinition.cs
index 4d25de9..2319b36 100644
--- a/Upsilon/BoundTypes/UserDataBoundTypeDefinition.cs
+++ b/Upsilon/BoundTypes/UserDataBoundTypeDefinition.cs
@@ -1,7 +1,9 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Reflection;
 using Upsilon.BaseTypes;
+using Upsilon.StandardLibraries;
 using Type = Upsilon.BaseTypes.Type;
 
 namespace Upsilon.BoundTypes
@@ -52,12 +54,25 @@ namespace Upsilon.BoundTypes
             {
                 obj.Properties.Add(f.Name.ToLowerInvariant(), f);
             }
-            var methods = backingType.GetMethods().Select(x => new UserDataBoundMethod()
+            var methods = new List<UserDataBoundMethod>();
+            var backingMethods = backingType.GetMethods();
+            foreach (var backingMethod in backingMethods)
             {
-                Name       = x.Name,
-                Type       = Type.Function,
-                ResultType = x.ReturnType.GetScriptType()
-            });
+                if (backingMethod.IsSpecialName)
+                    continue;
+                var name = backingMethod.Name;
+                var attribute = backingMethod.GetCustomAttribute(typeof(ScriptFunctionAttribute));
+                if (attribute is ScriptFunctionAttribute sfa )
+                {
+                    name = sfa.Name;
+                }
+                methods.Add(new UserDataBoundMethod()
+                {
+                    Name       = name,
+                    Type       = Type.Function,
+                    ResultType = backingMethod.ReturnType.GetScriptType()
+                });
+            }
             foreach (var f in methods)
             {
                 obj.Properties.Add(f.Name.ToLowerInvariant(), f);
diff --git a/Upsilon/StandardLibraries/BasicFunctions.cs b/Upsilon/StandardLibraries/BasicFunctions.cs
index 9d189c2..d862eef 100644
--- a/Upsilon/StandardLibraries/BasicFunctions.cs
+++ b/Upsilon/StandardLibraries/BasicFunctions.cs
@@ -13,8 +13,9 @@ namespace Upsilon.StandardLibraries
 {
     internal class BasicFunctions : ScriptLibrary
     {
-        [StandardLibraryScriptFunction("assert", "Asserts that the parameter passed is true. Throws an exception if it is not true. " +
-                                                 "Can take a message to show in the exception, otherwise throws with message \"assertion failed!\"")]
+        [ScriptFunction("assert", "Asserts that the parameter passed is true. Throws an exception if it is not true. " +
+                                                 "Can take a message to show in the exception, otherwise throws with message \"assertion failed!\"",
+            directScriptManipulation: true)]
         public void Assert(ScriptBoolean boolean, ScriptString message = null)
         {
             if (!boolean)
@@ -23,26 +24,29 @@ namespace Upsilon.StandardLibraries
             }
         }
 
-        [StandardLibraryScriptFunction("error", "Throw an exception with given error message")]
+        [ScriptFunction("error", "Throw an exception with given error message",
+            directScriptManipulation: true)]
         public void Error(ScriptString message)
         {
             throw new Exception(message.Value);
         }
 
-        [StandardLibraryScriptFunction("ipairs", "Iterates over an iterable variable, like a table, until it encounters a nil value.")]
+        [ScriptFunction("ipairs", "Iterates over an iterable variable, like a table, until it encounters a nil value.",
+            directScriptManipulation: true)]
         public IIterable UpTillNullPairs(IIterable table)
         {
             return new UpTillNullPairsScriptIterator(table);
         }
 
-        [StandardLibraryScriptFunction("pairs", "Iterates over an iterable variable, like a table, skipping all nil values.")]
+        [ScriptFunction("pairs", "Iterates over an iterable variable, like a table, skipping all nil values.",
+            directScriptManipulation: true)]
         public IIterable Pairs(IIterable table)
         {
             return new PairsScriptIterator(table);
         }
 
-        [StandardLibraryScriptFunction("require", "Loads a module from the module path, using the given script loader.",
-            true)]
+        [ScriptFunction("require", "Loads a module from the module path, using the given script loader.",
+            true, true)]
         public ScriptType Require(Script script, ScriptString fileName)
         {
             var file = fileName.Value;
@@ -57,7 +61,7 @@ namespace Upsilon.StandardLibraries
         }
 
 
-        [StandardLibraryScriptFunction("tonumber", "Parses a string to a number.")]
+        [ScriptFunction("tonumber", "Parses a string to a number.", directScriptManipulation: true)]
         public ScriptNumber ToNumber(ScriptString obj)
         {
             var str = obj.Value;
@@ -71,13 +75,13 @@ namespace Upsilon.StandardLibraries
             }
         }
 
-        [StandardLibraryScriptFunction("tostring", "Returns the string value of the given object.")]
+        [ScriptFunction("tostring", "Returns the string value of the given object.", directScriptManipulation: true)]
         public ScriptString ToString(ScriptType obj)
         {
             return new ScriptString(obj.ToString());
         }
 
-        [StandardLibraryScriptFunction("type", "Returns the type of the given object as a string.")]
+        [ScriptFunction("type", "Returns the type of the given object as a string.", directScriptManipulation: true)]
         public ScriptString Type(ScriptType obj)
         {
             return new ScriptString(obj.Type.ToString());
diff --git a/Upsilon/StandardLibraries/MathLibrary.cs b/Upsilon/StandardLibraries/MathLibrary.cs
new file mode 100644
index 0000000..0a1fb47
--- /dev/null
+++ b/Upsilon/StandardLibraries/MathLibrary.cs
@@ -0,0 +1,18 @@
+using System;
+using Upsilon.BaseTypes.Number;
+
+namespace Upsilon.StandardLibraries
+{
+    internal class MathLibrary
+    {
+        [ScriptFunction("abs", "Returns the absolute value of x. (integer/float)", directScriptManipulation: true)]
+        public ScriptNumber Absolute(ScriptNumber a)
+        {
+            if (a.IsFloat)
+            {
+                return new ScriptNumberDouble(Math.Abs(((ScriptNumberDouble) a).Value));
+            }
+            return new ScriptNumberLong(Math.Abs(((ScriptNumberLong) a).Value));
+        }
+    }
+}
\ No newline at end of file
diff --git a/Upsilon/StandardLibraries/StandardLibraryScriptFunctionAttribute.cs b/Upsilon/StandardLibraries/ScriptFunctionAttribute.cs
similarity index 58%
rename from Upsilon/StandardLibraries/StandardLibraryScriptFunctionAttribute.cs
rename to Upsilon/StandardLibraries/ScriptFunctionAttribute.cs
index a049259..2b5fe70 100644
--- a/Upsilon/StandardLibraries/StandardLibraryScriptFunctionAttribute.cs
+++ b/Upsilon/StandardLibraries/ScriptFunctionAttribute.cs
@@ -3,19 +3,21 @@ using System;
 namespace Upsilon.StandardLibraries
 {
     [AttributeUsage(AttributeTargets.Method, AllowMultiple = true, Inherited = true)]
-    public class StandardLibraryScriptFunctionAttribute : Attribute
+    public class ScriptFunctionAttribute : Attribute
     {
-        public StandardLibraryScriptFunctionAttribute(string name, string comment = null,
-            bool passScriptReference = false, bool passScopeReference = false)
+        public ScriptFunctionAttribute(string name, string comment = null,
+            bool directScriptManipulation = false, bool passScriptReference = false, bool passScopeReference = false)
         {
             Name = name;
             Comment = comment;
+            DirectScriptManipulation = directScriptManipulation;
             PassScriptReference = passScriptReference;
             PassScopeReference = passScopeReference;
         }
 
         public string Name { get; }
         public string Comment { get; }
+        public bool DirectScriptManipulation { get; }
         public bool PassScriptReference { get; }
         public bool PassScopeReference { get; }
     }
diff --git a/Upsilon/StandardLibraries/ScriptLibrary.cs b/Upsilon/StandardLibraries/ScriptLibrary.cs
index 9104931..daec8cf 100644
--- a/Upsilon/StandardLibraries/ScriptLibrary.cs
+++ b/Upsilon/StandardLibraries/ScriptLibrary.cs
@@ -14,7 +14,7 @@ namespace Upsilon.StandardLibraries
             var methods = GetType().GetMethods();
             foreach (var methodInfo in methods)
             {
-                var attr = methodInfo.GetCustomAttribute<StandardLibraryScriptFunctionAttribute>();
+                var attr = methodInfo.GetCustomAttribute<ScriptFunctionAttribute>();
                 if (attr != null)
                 {
                     dictionary.Add(attr.Name, new LoadedStandardFunction()
diff --git a/Upsilon/StandardLibraries/StaticScope.cs b/Upsilon/StandardLibraries/StaticScope.cs
index b3bc540..239edd9 100644
--- a/Upsilon/StandardLibraries/StaticScope.cs
+++ b/Upsilon/StandardLibraries/StaticScope.cs
@@ -6,6 +6,7 @@ using System.Linq;
 using Upsilon.BaseTypes;
 using Upsilon.BaseTypes.Number;
 using Upsilon.BaseTypes.ScriptTypeInterfaces;
+using Upsilon.BaseTypes.UserData;
 using Upsilon.Binder;
 using Upsilon.Binder.VariableSymbols;
 using Upsilon.BoundTypes;
@@ -68,6 +69,12 @@ namespace Upsilon.StandardLibraries
                 };
                 boundFuncs.Add(func.Key, functionSymbol);
             }
+
+            UserDataTypeHandler.LoadType<MathLibrary>();
+            funcs.Add("math", new MathLibrary().ToScriptType());
+            boundFuncs.Add("math",
+                new FunctionParameterSymbol("math", BoundTypeHandler.GetTypeDefinition(typeof(MathLibrary))));
+
             var scope = new EvaluationScope(funcs);
             var boundScope = new BoundScope(boundFuncs, null);
             return (scope, boundScope);
diff --git a/UpsilonTests/GeneralTests/BasicMathExpressions.cs b/UpsilonTests/GeneralTests/BasicMathExpressions.cs
index 9eef6ad..3fd56ee 100644
--- a/UpsilonTests/GeneralTests/BasicMathExpressions.cs
+++ b/UpsilonTests/GeneralTests/BasicMathExpressions.cs
@@ -50,7 +50,7 @@ namespace UpsilonTests.GeneralTests
         [Theory]
         [InlineData("1/1", 1)]
         [InlineData("1000 / 10", 100)]
-        [InlineData("656486 / 5146", 127)]
+        [InlineData("656486 / 5146", 127.57209483)]
         [InlineData("656486 / 5146.0", 127.57209483)]
         public void Divison(string input, double expectedOutput)
         {