diff --git a/functions.js b/functions.js
index f06bcee..0385477 100644
--- a/functions.js
+++ b/functions.js
@@ -4,20 +4,26 @@
  * @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) {
+	return n + 1;
+}
 
 /**
  * Subtracts one from a given number.
  * @param {number} n
  * @return {number}
  */
-
+function decrease(n) {
+	return n -1;
+}
 
 /**
  * Adds two numbers.
@@ -25,7 +31,9 @@
  * @param {number} y
  * @return {number} the sum
  */
-
+function add(a,b) {
+	return a + b;
+}
 
 /**
  * Subtracts the second number from the first.
@@ -33,15 +41,18 @@
  * @param {number} y
  * @return {number} the difference
  */
-
-
+function subtract(x,y) {
+	return x-y;
+}
 /**
  * Multiplies two numbers.
  * @param {number} x
  * @param {number} y
  * @return {number} the product
  */
-
+function multiply(x,y) {
+	return x * y;
+}
 
 /**
  * Divides the first number by the second.
@@ -49,14 +60,18 @@
  * @param {number} y
  * @return {number} the quotient
  */
-
+function divide(x,y) {
+	return x/y;
+}
 
 /**
  * Multiplies a number by itself.
  * @param {number} x, number to be squared
  * @return {number} squared
  */
-
+function square(n) {
+	return n * n;
+}
 
 /**
  * Performs a mathematical operation on two numbers.
@@ -66,15 +81,18 @@
  * @param {number} y
  * @return {number} the result
  */
-
-
+function mathematical(x,y) {
+	
+}
 /**
  * Returns true if `a` is greater than `b`.
  * @param {number} a
  * @param {number} b
  * @return {boolean} `a` is larger than `b`
  */
-
+function isGreaterThan(a,b) {
+	return a>b;
+}
 
 /**
  * Returns true if `a` is less than `b`.
@@ -82,7 +100,9 @@
  * @param {number} b
  * @return {boolean} `a` is smaller than `b`
  */
-
+function isLessThan(a,b) {
+	return a<b;
+}
 
 /**
  * Returns true if `a` and `b` are equal.
@@ -90,7 +110,9 @@
  * @param {number} b
  * @return {boolean} the numbers are equal
  */
-
+function areEqual(a,b) {
+	return a === b;
+}
 
 /**
  * Returns the smallest value of two numbers.
@@ -98,7 +120,9 @@
  * @param {number} y
  * @return {number} the smallest number
  */
-
+function minimum(x,y) {
+	return x <= y ? x : y;
+}
 
 /**
  * Returns the largest value of two numbers.
@@ -106,21 +130,27 @@
  * @param {number} y
  * @return {number} the largest number
  */
-
+function maximum(x,y) {
+	return x >= y ? x : y;
+}
 
 /**
  * Returns true if `n` is even.
  * @param {number} n
  * @return {boolean} the number is even
  */
-
+function isEven(n) {
+	return n % 2 === 0;
+}
 
 /**
  * Returns true if `n` is odd.
  * @param {number} n
  * @return {boolean} the number is odd
  */
-
+function isOdd(n) {
+	return n % 2 !== 0;
+}
 
 /**
  * Returns a letter grade.
@@ -133,7 +163,19 @@
  * @param {number} total maximum possible score
  * @return {string} the score represented as a letter grade
  */
-
+function letterGrade(score, total) {
+	var percent = score / total;
+	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.
@@ -142,15 +184,24 @@
  * @param {object} restaurant   represents a restaurant object
  * @return {object} restaurant
  */
-
-
+function incrementReviews(restaurant) {
+	if (restaurant.reviews) {
+		restaurant.reviews++;
+	}
+		else {
+			restaurant.reviews = 1;
+		}
+	return restaurant;
+}
 /**
  * Joins two strings with a space.
  * @param {string} word1
  * @param {string} word2
  * @return {string} joined the words joined with a space
  */
-
+function combine(word1, word2) {
+	return word1 + ' ' + word2;
+}
 
 /**
  * Returns a circle object with the properties `circumference` and `area`.
@@ -159,4 +210,10 @@
  * @param {number} radius
  * @return {object} circle
  */
-
+function createCircle(radius) {
+	var circle = {
+		circumference: 2 * Math.PI *radius,
+		area: Math.PI * (radius * radius)
+	}
+	return circle; 
+}