diff --git a/src/core/config/Categories.js b/src/core/config/Categories.js
index 0ab32eb1..8fc8ac02 100755
--- a/src/core/config/Categories.js
+++ b/src/core/config/Categories.js
@@ -128,7 +128,7 @@ const Categories = [
             "Rotate right",
             "ROT13",
             "Sum",
-            "Sub",
+            "Subtract",
             "Multiply",
             "Divide",
             "Mean",
@@ -166,7 +166,6 @@ const Categories = [
     {
         name: "Utils",
         ops: [
-            "Arithmetic",
             "Diff",
             "Remove whitespace",
             "Remove null bytes",
diff --git a/src/core/config/OperationConfig.js b/src/core/config/OperationConfig.js
index 9f41f2f8..93c82adf 100755
--- a/src/core/config/OperationConfig.js
+++ b/src/core/config/OperationConfig.js
@@ -658,9 +658,9 @@ const OperationConfig = {
             }
         ]
     },
-    "Arithmetic": {
+    "Sum": {
         module: "Default",
-        description: "Conducts mathamatical operations on a list of numbers",
+        description: "Sums a list of numbers. If an item in the string is not a number it is excluded from the list.<br><br>e.g. <code>0x0a 8 .5</code> becomes <code>18.5</code>",
         inputType: "string",
         outputType: "string",
         args: [
@@ -668,11 +668,84 @@ const OperationConfig = {
                 name: "Delimiter",
                 type: "option",
                 value: Arithmetic.DELIM_OPTIONS
-            },
+            }
+        ]
+    },
+    "Subtract": {
+        module: "Default",
+        description: "Subtracts a list of numbers. If an item in the string is not a number it is excluded from the list.<br><br>e.g. <code>0x0a 8 .5</code> becomes <code>1.5</code>",
+        inputType: "string",
+        outputType: "string",
+        args: [
             {
-                name: "Operation",
+                name: "Delimiter",
                 type: "option",
-                value: Arithmetic.OPERATIONS
+                value: Arithmetic.DELIM_OPTIONS
+            }
+        ]
+    },
+    "Multiply": {
+        module: "Default",
+        description: "Multiplies a list of numbers. If an item in the string is not a number it is excluded from the list.<br><br>e.g. <code>0x0a 8 .5</code> becomes <code>40</code>",
+        inputType: "string",
+        outputType: "string",
+        args: [
+            {
+                name: "Delimiter",
+                type: "option",
+                value: Arithmetic.DELIM_OPTIONS
+            }
+        ]
+    },
+    "Divide": {
+        module: "Default",
+        description: "Divides a list of numbers. If an item in the string is not a number it is excluded from the list.<br><br>e.g. <code>0x0a 8 .5</code> becomes <code>2.5</code>",
+        inputType: "string",
+        outputType: "string",
+        args: [
+            {
+                name: "Delimiter",
+                type: "option",
+                value: Arithmetic.DELIM_OPTIONS
+            }
+        ]
+    },
+    "Mean": {
+        module: "Default",
+        description: "Computes the mean (average) of a number list. If an item in the string is not a number it is excluded from the list.<br><br>e.g. <code>0x0a 8 .5 .5</code> becomes <code>4.75</code>",
+        inputType: "string",
+        outputType: "string",
+        args: [
+            {
+                name: "Delimiter",
+                type: "option",
+                value: Arithmetic.DELIM_OPTIONS
+            }
+        ]
+    },
+    "Median": {
+        module: "Default",
+        description: "Computes the median of a number list. If an item in the string is not a number it is excluded from the list.<br><br>e.g. <code>0x0a 8 1 .5</code> becomes <code>4.5</code>",
+        inputType: "string",
+        outputType: "string",
+        args: [
+            {
+                name: "Delimiter",
+                type: "option",
+                value: Arithmetic.DELIM_OPTIONS
+            }
+        ]
+    },
+    "Standard Deviation": {
+        module: "Default",
+        description: "Computes the standard deviation of a number list. If an item in the string is not a number it is excluded from the list.<br><br>e.g. <code>0x0a 8 .5</code> becomes <code>4.089281382128433</code>",
+        inputType: "string",
+        outputType: "string",
+        args: [
+            {
+                name: "Delimiter",
+                type: "option",
+                value: Arithmetic.DELIM_OPTIONS
             }
         ]
     },
diff --git a/src/core/config/modules/Default.js b/src/core/config/modules/Default.js
index 6f672ce2..9a373e12 100644
--- a/src/core/config/modules/Default.js
+++ b/src/core/config/modules/Default.js
@@ -157,7 +157,13 @@ OpModules.Default = {
     "Return":               FlowControl.runReturn,
     "Comment":              FlowControl.runComment,
     "PHP Deserialize":      PHP.runDeserialize,
-    "Arithmetic":           Arithmetic.runOp,
+    "Sum":                  Arithmetic.runSum,
+    "Subtract":             Arithmetic.runSub,
+    "Multiply":             Arithmetic.runMulti,
+    "Divide":               Arithmetic.runDiv,
+    "Mean":                 Arithmetic.runMean,
+    "Median":               Arithmetic.runMedian,
+    "Standard Deviation":   Arithmetic.runStdDev,
 
 
     /*
diff --git a/src/core/operations/Arithmetic.js b/src/core/operations/Arithmetic.js
index 6472a7fc..9b07f8ad 100644
--- a/src/core/operations/Arithmetic.js
+++ b/src/core/operations/Arithmetic.js
@@ -17,72 +17,107 @@ const Arithmetic = {
      */
     DELIM_OPTIONS: ["Space", "Comma", "Semi-colon", "Colon", "Line feed", "CRLF"],
 
-    /**
-     * @constant
-     * @default
-     */
-    OPERATIONS: [
-        "Sum",
-        "Sub",
-        "Multiply",
-        "Divide",
-        "Mean",
-        "Median",
-        "Standard Deviation"
-    ],
-
 
     /**
-     *
+     * Splits a string based on a delimiter and calculates the sum of numbers.
      *
      * @param {string} input
      * @param {Object[]} args
-     * @returns {number}
+     * @returns {string}
      */
-    computeSum: function(input, args) {
+    runSum: function(input, args) {
         const val = Arithmetic._sum(Arithmetic._createNumArray(input, args[0]));
-        return typeof(val) === 'number' ? val.toString() : "";
+        return typeof(val) === "number" ? val.toString() : "";
     },
 
 
-    computeSub: function(input, args) {
+    /**
+     * Splits a string based on a delimiter and subtracts all the numbers.
+     *
+     * @param {string} input
+     * @param {Object[]} args
+     * @returns {string}
+     */
+    runSub: function(input, args) {
         let val = Arithmetic._sub(Arithmetic._createNumArray(input, args[0]));
-        return typeof(val) === 'number' ? val.toString() : "";
+        return typeof(val) === "number" ? val.toString() : "";
     },
 
 
-    computeMulti: function(input, args) {
+    /**
+     * Splits a string based on a delimiter and multiplies the numbers.
+     *
+     * @param {string} input
+     * @param {Object[]} args
+     * @returns {string}
+     */
+    runMulti: function(input, args) {
         let val = Arithmetic._multi(Arithmetic._createNumArray(input, args[0]));
-        return typeof(val) === 'number' ? val.toString() : "";
+        return typeof(val) === "number" ? val.toString() : "";
     },
 
 
-    computeDiv: function(input, args) {
+    /**
+     * Splits a string based on a delimiter and divides the numbers.
+     *
+     * @param {string} input
+     * @param {Object[]} args
+     * @returns {string}
+     */
+    runDiv: function(input, args) {
         let val = Arithmetic._div(Arithmetic._createNumArray(input, args[0]));
-        return typeof(val) === 'number' ? val.toString() : "";
+        return typeof(val) === "number" ? val.toString() : "";
     },
 
 
-    computeMean: function(input, args) {
+    /**
+     * Splits a string based on a delimiter and computes the mean (average).
+     *
+     * @param {string} input
+     * @param {Object[]} args
+     * @returns {string}
+     */
+    runMean: function(input, args) {
         let val = Arithmetic._mean(Arithmetic._createNumArray(input, args[0]));
-        return typeof(val) === 'number' ? val.toString() : "";
+        return typeof(val) === "number" ? val.toString() : "";
     },
 
 
-    computeMedian: function(input, args) {
+    /**
+     * Splits a string based on a delimiter and finds the median.
+     *
+     * @param {string} input
+     * @param {Object[]} args
+     * @returns {string}
+     */
+    runMedian: function(input, args) {
         let val = Arithmetic._median(Arithmetic._createNumArray(input, args[0]));
-        return typeof(val) === 'number' ? val.toString() : "";
+        return typeof(val) === "number" ? val.toString() : "";
     },
 
 
-    computeStdDev: function(input, args) {
+    /**
+     * splits a string based on a delimiter and computes the standard deviation.
+     *
+     * @param {string} input
+     * @param {Object[]} args
+     * @returns {string}
+     */
+    runStdDev: function(input, args) {
         let val = Arithmetic._stdDev(Arithmetic._createNumArray(input, args[0]));
-        return typeof(val) === 'number' ? val.toString() : "";
+        return typeof(val) === "number" ? val.toString() : "";
     },
 
 
+    /**
+     * Converts a string array to a number array.
+     *
+     * @param {string[]} input
+     * @param {string} delim
+     * @returns {number[]}
+     */
     _createNumArray: function(input, delim) {
-        const delim = Utils.charRep[delim || "Space"];
+        delim = Utils.charRep[delim || "Space"];
         let splitNumbers = input.split(delim),
             numbers = [],
             num;
@@ -153,7 +188,7 @@ const Arithmetic = {
     },
 
     /**
-     * Finds the mean of a number array and returns the value.
+     * Computes mean of a number array and returns the value.
      *
      * @private
      * @param {number[]} data
@@ -166,7 +201,7 @@ const Arithmetic = {
     },
 
     /**
-     * Finds the median of a number array and returns the value.
+     * Computes median of a number array and returns the value.
      *
      * @private
      * @param {number[]} data
@@ -187,7 +222,7 @@ const Arithmetic = {
     },
 
     /**
-     * Finds the standard deviation of a number array and returns the value.
+     * Computes standard deviation of a number array and returns the value.
      *
      * @private
      * @param {number[]} data