diff --git a/index.js b/index.js
index e37f41ec7..d0d2063c7 100644
--- a/index.js
+++ b/index.js
@@ -17,6 +17,7 @@ function myFunction() {
 
 //🚀🚀🚀 ⬇️ 📝 Explanation ⬇️ 📝 🚀🚀🚀: 
 
+//Because the internal const was defined within the myFunction scope. 
 
 
 
@@ -30,9 +31,12 @@ function myFunction() {
 💡 NOTE: you may use a for loop for this function if you wish 
 */
 
-function summation(/*Your Code Here*/) {
-  /*Your Code Here*/
-
+function summation(num) {
+  let sum = 0
+  for(let i = 0;i<num;i++){
+    sum = sum + (i+1)
+  }
+  return sum
   }
  
 
@@ -60,8 +64,10 @@ const zooAnimals = [
   💡 NOTE: the array returned should be an array of strings, and each string should follow this pattern: "name: {name}, scientific: {scientific name}"
   */
 
-  function animalNames(/*Your Code Here*/){
-    /*Your Code Here*/
+  function animalNames(arr){
+    const displayNames = []
+    arr.forEach((element) => displayNames.push(`name: ${element.animal_name}, scientific: ${element.scientific_name}`))
+    return(displayNames)
   }
   
 
@@ -75,8 +81,9 @@ const zooAnimals = [
   💡 NOTE: Do some research for other methods that can help help you
   */
 
-  function lowerCaseNames(/*Your Code Here*/){
-    /*Your Code Here*/
+  function lowerCaseNames(arr){
+    const lowerAnimals = arr.map(x => x.animal_name.toLowerCase())
+    return(lowerAnimals)
   }
   
   
@@ -88,8 +95,9 @@ const zooAnimals = [
   3. Return this new array
   */
 
-  function lowPopulationAnimals(/*Your Code Here*/){
-    /*Your Code Here*/
+  function lowPopulationAnimals(arr){
+    const lowPop = arr.filter(element => element.population < 5)
+    return lowPop
   }
   
 
@@ -102,8 +110,8 @@ const zooAnimals = [
   💡 NOTE: Remember the reduce method takes two arguments: a callback (which itself takes two args - the accumulator and the item), and an initial value for the count. Check MDN/W3Schools for syntax!
   */
 
-  function USApop(/*Your Code Here*/){
-    /*Your Code Here*/
+  function USApop(arr){
+    return(arr.reduce((pv,cv) => pv + cv.population,0))
   }
   
   
@@ -116,8 +124,8 @@ const zooAnimals = [
     💡 NOTE: The tests for 'consume' will pass if it is created correctly and also after you correctly complete the functions 'add' and 'greeting' below in Step 2.
   */
 
-  function consume(/*Your Code Here */){
-    /*Your Code Here */
+  function consume(a,b,cb){
+    return cb(a,b)
   }
  
   
@@ -128,8 +136,8 @@ const zooAnimals = [
  2. Return the sum of those numbers
  */
 
-function add(/*Your Code Here */){
-    /*Your Code Here*/
+function add(a,b){
+    return a + b
   }
 
 
@@ -138,8 +146,8 @@ function add(/*Your Code Here */){
 2. Return the product of those numbers
 */
 
-function multiply(/*Your Code Here */){
-   /*Your Code Here */
+function multiply(a,b){
+   return a * b
   }
 
 
@@ -149,8 +157,8 @@ function multiply(/*Your Code Here */){
 💡 NOTE: The string returned must match the format above or the test will not pass!
 */
 
-function greeting(/*Your Code Here */){
-   return /*Your Code Here */
+function greeting(a,b){
+   return (`Hello ${a} ${b}, nice to meet you!`)
   }
   
   
@@ -175,9 +183,11 @@ function greeting(/*Your Code Here */){
 - Instances of CuboidMaker should initialize `length`, `width` and `height` properties
 */
 
-function CuboidMaker(/*Your Code Here */){
-  /*Your Code Here */
-}
+function CuboidMaker(dimensions){
+  this.length = dimensions.length
+  this.width = dimensions.width
+  this.height = dimensions.height
+  }
 
 
 /* 🐴🐴🐴 Step 2: Volume Method 🐴🐴🐴
@@ -185,7 +195,10 @@ function CuboidMaker(/*Your Code Here */){
   💡 NOTE: Formula for cuboid volume: length * width * height   
 */
 
-
+CuboidMaker.prototype.volume = function() {
+  return this.length * this.width * this.height
+}
+  
 
 
 /* 🐴🐴🐴 Step 3: Surface Area Method 🐴🐴🐴
@@ -193,14 +206,20 @@ function CuboidMaker(/*Your Code Here */){
   💡 NOTE: Formula for cuboid surface area: 2 * (length * width + length * height + width * height)  
 */
 
-
+CuboidMaker.prototype.surfaceArea = function() {
+  return 2 * ((this.length * this.width) + (this.length * this.height) + (this.width * this.height))
+}
 
 
 /* 🐴🐴🐴 Step 4: Create a new object that uses CuboidMaker (not auto graded)🐴🐴🐴
   Create an object called cuboid that uses the new keyword to use our CuboidMaker constructor
   Add properties and values of length: 4, width: 5, and height: 5 to cuboid. */
 
-
+const cuboid = new CuboidMaker ({
+  length: 4,
+  width: 5,
+  height: 5
+})
 
 
 
@@ -214,7 +233,17 @@ function CuboidMaker(/*Your Code Here */){
 //Using CuboidMakerTwo, take your prototypes from above and refactor into class syntax. Then, create an object called cuboidTwo that uses the new keyword to use our CuboidMakerTwo class.
  
 class CuboidMakerTwo{
-
+  constructor(attrs) {
+    this.height = attrs.height
+    this.length = attrs.length
+    this.width = attrs.width
+  }
+  surfaceArea() {
+      return 2 * ((this.length * this.width) + (this.length * this.height) + (this.width * this.height))
+    }
+  volume() {
+    return this.length * this.width * this.height
+  }
 }