diff --git a/index.js b/index.js
index 3bb4d07..477dee0 100644
--- a/index.js
+++ b/index.js
@@ -4,7 +4,38 @@
  * Depending on the operation, either add up all of the numbers or subtract all of the numbers, from left to right.
  * @returns {number} The result of either adding all numbers or subtracting all numbers, depending on the arguments added to the command line.
  */
-function calculator() {}
 
+
+
+
+
+function calculator(){
+     let theOperator =  process.argv[2] //
+     let sum = 0
+  if (!theOperator) {  //Deteremine if this variable does not contains "theOperator"? by signify with the "!" operator. 
+        return "No operation provided...";  //Determined that there was not "theOperator" thus returning the "No operation provided.."statement!
+    } else if (theOperator !== "plus" && theOperator != "minus"){ // If no mathmatical expression is provided either "plus" or "minus".
+        return `Invalid operation: ${theOperator}`; // Return the response of "Invalid operator :" + my variable of "theOperator" I used `string interpelation` in order to combine my return values. 
+    }
+
+     let numbers = process.argv.slice(3); //Created "numbers" variable equal to my [3] index of my array by creating new copy of to iterate by using the .slice() method becuase we know the "numbers" start at that index of the array!
+     if (numbers.length === 0){  // if != No number is provided through length of the array!
+          return "No numbers provided..." // Then return the response of "No numbers provided..."
+     }
+   
+     for(let num of numbers){ // While looping through the array of numbers
+
+          console.log (num)
+          if (theOperator === "plus"){ // Checking if "theOperator" is equal to "plus"
+               return sum = numbers.reduce((preiousVal, currentVal) => Number(preiousVal) + Number (currentVal)); // With the .reduce method I used to take two values from the prevVal and currentVal and manipulate my array to  add the values!
+          }
+          }
+
+      if ( theOperator === "minus"){ 
+    // With the .reduce method I used to take two values from the prevVal and currentVal and manipulate my array to the last value!
+
+      return sum = numbers.reduce((preiousVal, currentVal) => Number(preiousVal) - Number (currentVal)) 
+}}
 // Don't change anything below this line.
 module.exports = calculator;
+
diff --git a/package-lock.json b/package-lock.json
index 4d451a9..e0f6e26 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -2873,13 +2873,10 @@
       }
     },
     "node_modules/json5": {
-      "version": "2.2.0",
-      "resolved": "https://registry.npmjs.org/json5/-/json5-2.2.0.tgz",
-      "integrity": "sha512-f+8cldu7X/y7RAJurMEJmdoKXGB/X550w2Nr3tTbezL6RwEE/iMcm+tZnXeoZtKuOq6ft8+CqzEkrIgx1fPoQA==",
+      "version": "2.2.3",
+      "resolved": "https://registry.npmjs.org/json5/-/json5-2.2.3.tgz",
+      "integrity": "sha512-XmOWe7eyHYH14cLdVPoyg+GOH3rYX++KpzrylJwSW98t3Nk+U8XOl8FWKOgwtzdb8lXGf6zYwDUzeHMWfxasyg==",
       "dev": true,
-      "dependencies": {
-        "minimist": "^1.2.5"
-      },
       "bin": {
         "json5": "lib/cli.js"
       },
@@ -3022,9 +3019,9 @@
       }
     },
     "node_modules/minimatch": {
-      "version": "3.0.4",
-      "resolved": "https://registry.npmjs.org/minimatch/-/minimatch-3.0.4.tgz",
-      "integrity": "sha512-yJHVQEhyqPLUTgt9B83PXu6W3rx4MvvHvSUvToogpwoGDOUQ+yDrR0HRot+yOCdCO7u4hX3pWft6kWBBcqh0UA==",
+      "version": "3.1.2",
+      "resolved": "https://registry.npmjs.org/minimatch/-/minimatch-3.1.2.tgz",
+      "integrity": "sha512-J7p63hRiAjw1NDEww1W7i37+ByIrOWO5XQQAzZ3VOcL0PNybwpfmV/N05zFAzwQ9USyEcX6t3UO+K5aqBQOIHw==",
       "dev": true,
       "dependencies": {
         "brace-expansion": "^1.1.7"
@@ -3033,12 +3030,6 @@
         "node": "*"
       }
     },
-    "node_modules/minimist": {
-      "version": "1.2.6",
-      "resolved": "https://registry.npmjs.org/minimist/-/minimist-1.2.6.tgz",
-      "integrity": "sha512-Jsjnk4bw3YJqYzbdyBiNsPWHPfO++UGG749Cxs6peCu5Xg4nrena6OVxOYxrQTqww0Jmwt+Ref8rggumkTLz9Q==",
-      "dev": true
-    },
     "node_modules/ms": {
       "version": "2.1.2",
       "resolved": "https://registry.npmjs.org/ms/-/ms-2.1.2.tgz",
@@ -6180,13 +6171,10 @@
       "dev": true
     },
     "json5": {
-      "version": "2.2.0",
-      "resolved": "https://registry.npmjs.org/json5/-/json5-2.2.0.tgz",
-      "integrity": "sha512-f+8cldu7X/y7RAJurMEJmdoKXGB/X550w2Nr3tTbezL6RwEE/iMcm+tZnXeoZtKuOq6ft8+CqzEkrIgx1fPoQA==",
-      "dev": true,
-      "requires": {
-        "minimist": "^1.2.5"
-      }
+      "version": "2.2.3",
+      "resolved": "https://registry.npmjs.org/json5/-/json5-2.2.3.tgz",
+      "integrity": "sha512-XmOWe7eyHYH14cLdVPoyg+GOH3rYX++KpzrylJwSW98t3Nk+U8XOl8FWKOgwtzdb8lXGf6zYwDUzeHMWfxasyg==",
+      "dev": true
     },
     "kleur": {
       "version": "3.0.3",
@@ -6290,20 +6278,14 @@
       "dev": true
     },
     "minimatch": {
-      "version": "3.0.4",
-      "resolved": "https://registry.npmjs.org/minimatch/-/minimatch-3.0.4.tgz",
-      "integrity": "sha512-yJHVQEhyqPLUTgt9B83PXu6W3rx4MvvHvSUvToogpwoGDOUQ+yDrR0HRot+yOCdCO7u4hX3pWft6kWBBcqh0UA==",
+      "version": "3.1.2",
+      "resolved": "https://registry.npmjs.org/minimatch/-/minimatch-3.1.2.tgz",
+      "integrity": "sha512-J7p63hRiAjw1NDEww1W7i37+ByIrOWO5XQQAzZ3VOcL0PNybwpfmV/N05zFAzwQ9USyEcX6t3UO+K5aqBQOIHw==",
       "dev": true,
       "requires": {
         "brace-expansion": "^1.1.7"
       }
     },
-    "minimist": {
-      "version": "1.2.6",
-      "resolved": "https://registry.npmjs.org/minimist/-/minimist-1.2.6.tgz",
-      "integrity": "sha512-Jsjnk4bw3YJqYzbdyBiNsPWHPfO++UGG749Cxs6peCu5Xg4nrena6OVxOYxrQTqww0Jmwt+Ref8rggumkTLz9Q==",
-      "dev": true
-    },
     "ms": {
       "version": "2.1.2",
       "resolved": "https://registry.npmjs.org/ms/-/ms-2.1.2.tgz",