diff --git a/functions.js b/functions.js
index f06bcee..e80d1a9 100644
--- a/functions.js
+++ b/functions.js
@@ -4,20 +4,30 @@
  * @return {string} the number as a string
  */
 
+function numberToString(n) {
+	return "" + n;
+	
+}
 
 /**
  * Adds one to a given number.
  * @param {number} n
  * @return {number}
  */
-
+function increase(n){
+	 n++;
+	 return n;
+}
 
 /**
  * Subtracts one from a given number.
  * @param {number} n
  * @return {number}
  */
-
+function decrease(n){
+	n--;
+	return n;
+}
 
 /**
  * Adds two numbers.
@@ -25,6 +35,10 @@
  * @param {number} y
  * @return {number} the sum
  */
+ function add(x,y){
+ 	var sum= x + y;
+ 	return sum;
+ }
 
 
 /**
@@ -34,6 +48,11 @@
  * @return {number} the difference
  */
 
+ function subtract(x,y){
+ 	var difference = x - y;
+ 	return difference;
+ }
+
 
 /**
  * Multiplies two numbers.
@@ -42,6 +61,11 @@
  * @return {number} the product
  */
 
+ function multiply(x,y){
+ 	var product = x * y;
+ 	return product;
+ }
+
 
 /**
  * Divides the first number by the second.
@@ -50,6 +74,10 @@
  * @return {number} the quotient
  */
 
+function divide(x,y) {
+	var quotient= x / y;
+	return quotient;
+}
 
 /**
  * Multiplies a number by itself.
@@ -57,6 +85,11 @@
  * @return {number} squared
  */
 
+ function square(x) {
+ 	var squared = Math.pow(x,2);
+ 	return squared;
+ }
+
 
 /**
  * Performs a mathematical operation on two numbers.
@@ -67,6 +100,32 @@
  * @return {number} the result
  */
 
+function calculate(operation, x, y) { 
+
+	var result=0;
+
+ 	if (operation == "add") {
+ 		result = x+y;
+ 		console.log(x + " + " + y + " = " + result);
+ 		return result;
+ 	} 
+ 	 else if (operation == "subtract") {
+ 		result=x-y;
+ 		console.log(x + " - " + y + " = " + result);
+ 		return result;
+ 	}
+ 	 else if (operation==="multiply") {
+ 		result=x*y;
+ 		console.log(x + " * " + y + " = " + result);
+ 		return result;
+ 	}
+ 	 if (operation=="divide") {
+ 		result=x/y;
+ 	    console.log(x + " / " + y + " = " + result);
+ 	    return result;
+ 	}
+ }
+
 
 /**
  * Returns true if `a` is greater than `b`.
@@ -75,6 +134,10 @@
  * @return {boolean} `a` is larger than `b`
  */
 
+ function isGreaterThan(a,b) {
+ 	return a > b;
+ }
+
 
 /**
  * Returns true if `a` is less than `b`.
@@ -83,6 +146,9 @@
  * @return {boolean} `a` is smaller than `b`
  */
 
+function isLessThan(a,b) {
+	return a < b;
+}
 
 /**
  * Returns true if `a` and `b` are equal.
@@ -91,6 +157,9 @@
  * @return {boolean} the numbers are equal
  */
 
+function areEqual(a,b) {
+	return a === b;
+	} 
 
 /**
  * Returns the smallest value of two numbers.
@@ -99,6 +168,12 @@
  * @return {number} the smallest number
  */
 
+ function minimum(a,b){
+ 	var smallest = Math.min(a,b);
+
+ 		return smallest;
+ }
+
 
 /**
  * Returns the largest value of two numbers.
@@ -107,6 +182,11 @@
  * @return {number} the largest number
  */
 
+function maximum(x,y) {
+	var largest = Math.max(x,y);
+
+	return largest;
+}
 
 /**
  * Returns true if `n` is even.
@@ -114,6 +194,12 @@
  * @return {boolean} the number is even
  */
 
+function isEven(n){
+	if(n % 2 == 0){
+			return true;
+		}
+}
+
 
 /**
  * Returns true if `n` is odd.
@@ -121,6 +207,12 @@
  * @return {boolean} the number is odd
  */
 
+ function isOdd(n){
+ 	if(n % 2 !== 0){
+ 		return true;
+ 	}
+ }
+
 
 /**
  * Returns a letter grade.
@@ -134,6 +226,26 @@
  * @return {string} the score represented as a letter grade
  */
 
+function letterGrade(score,total){
+	var percent = Math.floor((score/total)*100);
+	
+	if (percent >= 90){
+		return "A";
+	}
+	else if(percent >= 80){
+		return "B";
+	}
+	else if(percent >= 70){
+		return "C";
+	}
+	else if(percent >= 60){
+		return "D";
+	}
+	else 
+		return "F";
+
+}
+
 
 /**
  * Checks if a `restaurant` object has a `reviews` property.
@@ -142,7 +254,16 @@
  * @param {object} restaurant   represents a restaurant object
  * @return {object} restaurant
  */
+function incrementReviews(restaurant){
+	console.log(restaurant);
 
+	if(restaurant.reviews != undefined){
+		restaurant.reviews++;
+	}else{
+		restaurant.reviews = 1;
+	}
+	return restaurant;
+}
 
 /**
  * Joins two strings with a space.
@@ -151,6 +272,10 @@
  * @return {string} joined the words joined with a space
  */
 
+ function combine(word1,word2) {
+ 	var combined= word1 + " " + word2;
+ 	return combined;
+}
 
 /**
  * Returns a circle object with the properties `circumference` and `area`.
@@ -160,3 +285,10 @@
  * @return {object} circle
  */
 
+function createCircle(radius) {
+	var circle = {};
+    circle.circumference = 2 * Math.PI * radius;
+    circle.area = Math.PI * (radius * radius);
+    return circle;
+}
+