Fix errors with spelling and grammar. Also changed the test mode cond…

…itional to allow "127.0.0.1".

Test plan:  Try out each exercise that I have modified, while using hints.

exercises/absolute_value_equations.html

@@ -118,10 +118,10 @@
 				</div>
 			</div>
 			<p data-if="( D - B ) / ( A - C ) > 0">
-				So, the correct answer is <code><var>SOLUTION</var></code>.
+				Thus, the correct answer is <code><var>SOLUTION</var></code>.
 			</p>
 			<p data-else>
-				The absolute value can not be negative. So, there is no solution.
+				The absolute value cannot be negative. Therefore, there is no solution.
 			</p>
 		</div>
 	</div>

exercises/angles_1.html

@@ -662,7 +662,7 @@
 
 					<p>
 						<code>\color{purple}{\angle{DAK}} = 90&deg;</code>,  
-						because angles formed by perpendicular lines equal to 90&deg;.
+						because angles formed by perpendicular lines are equal to 90&deg;.
 						<span class="graphie" data-update="alternate-exterior-and-complementary">
 							label( [-1.68, 2], "\\color{purple}{90&deg;}", "above left" );
 							arc( [0, 2], 1.65, 90, 180, {stroke: "purple"} );
@@ -726,4 +726,4 @@
 	</div> <!-- End of exercises -->
 </body>
 </html>
-<!-- EOF -->
+<!-- EOF -->

exercises/angles_2.html

@@ -390,7 +390,7 @@
 							\color{purple}{\angle{BHD}} = 
 							180° - \color{green}{\angle{BDC}} - \color{orange}{\angle{DBE}} = 
 							<var>Tri_Z</var>&deg;.
-						</code> This is because interior angles of a triangle add up to 180&deg;.
+						</code> This is because the interior angles of a triangle add up to 180&deg;.
 						<span class="graphie" data-update="star1">
 							// label angle BHD
 							arc([3.2, 1.3], .75, 118, 220, { stroke: "purple" });

exercises/comparing_fractions_1.html

@@ -98,7 +98,7 @@
 				<div class="hints">
 					<div>
 						<p>This is like considering two equally sized pizzas that have been cut into <var>DEN_1</var> equal slices.</p>
-						<p>Since both pizzas have the same number of slices, all the slice are the same size.</p>
+						<p>Since both pizzas have the same number of slices, all the slices are the same size.</p>
 						<div style="height: 150px;">
 							<div class="graphie" style="float: left">
 								init({ range: [ [-3, 3], [-3, 3] ], scale: 25 });

exercises/dependent_probability.html

@@ -96,7 +96,7 @@
 
 		<div class="hints">
 			<!-- hint indicating different coin types -->
-			<p>You can only possibly pick a fair coin or pick an unfair coin. There is no other outcome.</p>
+			<p>You can only pick a fair coin or pick an unfair coin. There is no other outcome.</p>
 
 			<!-- hint questioning coin type selection chances -->
 			<p>What chance do you have of picking an unfair coin? How about a fair coin?</p>

exercises/equation_of_a_circle_2.html

@@ -36,7 +36,7 @@
 						F === 0 ? null : F
 					])</var> = 0</code>.</p>
 
-				<p>What are its center <code>(h, k)</code> and its radius <code>r</code>?</p>
+				<p>What is its center <code>(h, k)</code> and its radius <code>r</code>?</p>
 
 			</div>
 

exercises/equivalent_fractions_2.html

@@ -22,7 +22,7 @@
 			</div>
 			<div class="solution"><var>D</var></div>
 			<div class="hints">
-				<p>To get the right numerator <code><var>C</var></code>, the left numerator <code><var>A</var></code> was multiplied by <code><var>M</var></code>.</p>
+				<p>To get the right numerator <code><var>C</var></code>, the left numerator <code><var>A</var></code> is multiplied by <code><var>M</var></code>.</p>
 				<p>To find the right denominator, multiply the left denominator by <code><var>M</var></code> as well.</p>
 				<p><code><var>B</var> \times <var>M</var> = <var>D</var></code></p>
 			</div>
@@ -34,7 +34,7 @@
 			</div>
 			<div class="solution"><var>C</var></div>
 			<div class="hints">
-				<p>To get the right denominator <code><var>D</var></code>, the left denominator <code><var>B</var></code> was multiplied by <code><var>M</var></code>.</p>
+				<p>To get the right denominator <code><var>D</var></code>, the left denominator <code><var>B</var></code> is multiplied by <code><var>M</var></code>.</p>
 				<p>To find the right numerator, multiply the left numerator by <code><var>M</var></code> as well.</p>
 				<p><code><var>A</var> \times <var>M</var> = <var>C</var></code></p>
 			</div>
@@ -46,7 +46,7 @@
 			</div>
 			<div class="solution"><var>B</var></div>
 			<div class="hints">
-				<p>To get the right numerator <code><var>A</var></code>, the left numerator <code><var>C</var></code> was divided by <code><var>M</var></code>.</p>
+				<p>To get the right numerator <code><var>A</var></code>, the left numerator <code><var>C</var></code> is divided by <code><var>M</var></code>.</p>
 				<p>To find the right denominator, divide the left denominator by <code><var>M</var></code> as well.</p>
 				<p><code><var>D</var> \div <var>M</var> = <var>B</var></code></p>
 			</div>
@@ -58,7 +58,7 @@
 			</div>
 			<div class="solution"><var>A</var></div>
 			<div class="hints">
-				<p>To get the right denominator <code><var>B</var></code>, the left denominator <code><var>D</var></code> was divided by <code><var>M</var></code>.</p>
+				<p>To get the right denominator <code><var>B</var></code>, the left denominator <code><var>D</var></code> is divided by <code><var>M</var></code>.</p>
 				<p>To find the right numerator, divide the left numerator by <code><var>M</var></code> as well.</p>
 				<p><code><var>C</var> \div <var>M</var> = <var>A</var></code></p>
 			</div>

exercises/graphs_of_sine_and_cosine.html

@@ -94,15 +94,15 @@
 
 				<p>The function starts at its maximum value (ie, <code>f(0)=<var>VSCALE</var></code>), so what kind of function is it?</p>
 
-				<p>The cosine function, <code>\cos(x)</code> starts at 1 (ie, <code>\cos(0)=1</code>), so <code>f(x)</code> must be a scaled version of the cosine function.</p>
+				<p>The cosine function, <code>\cos(x)</code>, starts at 1 (ie, <code>\cos(0)=1</code>), so <code>f(x)</code> must be a scaled version of the cosine function.</p>
 
 			</div>
 
 			<div data-else data-unwrap>
 
 				<p>The function starts at zero (ie, <code>f(0)=0</code>), so what kind of function is it?</p>
 
-				<p>The sine function, <code>\sin(x)</code> starts at 0 (ie, <code>\sin(0)=0</code>), so <code>f(x)</code> must be a scaled version of the sine function.</p>
+				<p>The sine function, <code>\sin(x)</code>, starts at 0 (ie, <code>\sin(0)=0</code>), so <code>f(x)</code> must be a scaled version of the sine function.</p>
 
 			</div>
 
@@ -123,14 +123,14 @@
 			</div>
 
 			<div data-if="abs( PERIOD - 2 * PI ) < 0.01" data-unwrap>
-				<p>The period of a normal <var>FNS</var> function is <code>2\pi</code>, and the period we want is <code><var>piFraction( PERIOD )</var></code>, so we don't need to worry about scaling the function horizantally.</p>
+				<p>The period of a normal <var>FNS</var> function is <code>2\pi</code>, and the period we want is <code><var>piFraction( PERIOD )</var></code>, so we don't need to worry about scaling the function horizontally.</p>
 			</div>
 
 			<div data-else data-unwrap>
 
 				<p>The period of a normal <var>FNS</var> function is <code>2\pi</code>, and the period we want is <code><var>piFraction( PERIOD )</var></code>, so we need to scale the <var>FNS</var> function horizontally by <code><var>decFrac( PERIOD / 2 / PI )</var></code>.</p>
 
-				<p>To horizontally scale <code>\<var>FN</var>(x)</code> by <code><var>decFrac( PERIOD / 2 / PI )</var></code>, we need to subsitute <code><var>decFrac( 2 * PI / PERIOD )</var>x</code> in for <code>x</code> to get <code>\<var>FN</var>(<var>decFrac( 2 * PI / PERIOD )</var>x)</code>.</p>
+				<p>To horizontally scale <code>\<var>FN</var>(x)</code> by <code><var>decFrac( PERIOD / 2 / PI )</var></code>, we need to substitute <code><var>decFrac( 2 * PI / PERIOD )</var>x</code> in for <code>x</code> to get <code>\<var>FN</var>(<var>decFrac( 2 * PI / PERIOD )</var>x)</code>.</p>
 
 			</div>
 

exercises/prime_factorization.html

@@ -17,7 +17,7 @@
 						<var id="NUMBER">getPrime()</var>
 					</div>
 					<p class="question">What is the prime factorization of <code><var>NUMBER</var></code>?</p>
-					<p>Type each prime factor separated by an x, like this: 2 x 3.</p>
+					<p>Type each prime factor separated by an x (as in the letter), like this: 2 x 3.</p>
 					<p class="solution"><var>NUMBER</var></p>
 					<div class="hints">
 						<p>Let us draw a factor tree.</p>
@@ -48,7 +48,7 @@
 					</div>
 
 					<p class="question">What is the prime factorization of <code><var>NUMBER</var></code>?</p>
-					<p>Type each prime factor separated by an x, like this: 2 x 3.</p>
+					<p>Type each prime factor separated by an x (as in the letter), like this: 2 x 3.</p>
 					<p class="solution" data-type="primeFactorization"><var>SOLUTION.join("x")</var></p>
 
 					<div class="hints">

exercises/solid_geometry.html

@@ -29,7 +29,7 @@
 			<p class="solution"><var>s * s * s</var></p>
 
 			<div class="hints">
-				<p>The volume of a cube with side <code>s</code> is <code>V = s^3</code>.</p>
+				<p>The volume of a cube with side length <code>s</code> is <code>V = s^3</code>.</p>
 				<p><code>\qquad V = <var>s</var>^3</code></p>
 				<p><code>\qquad \hphantom{V} = <var>s</var> \cdot <var>s</var> \cdot <var>s</var></code></p>
 				<p><code>\qquad \hphantom{V} = <var>s * s * s</var></code></p>

exercises/solving_for_a_variable.html

@@ -296,7 +296,7 @@
 					<p><code><var>X</var> = \dfrac{ <var>plus( (E*C)+Z, (-B*F)+Y )</var> }{ <var>color( A*F-D*C, false )</var> }</code></p>
 
 					<div data-if="GCD > 1 || (A*F-D*C) < 0" data-unwrap>
-						<p data-if="GCD > 1">All of these terms are divisable by <code><var>GCD</var></code>.</p>
+						<p data-if="GCD > 1">All of these terms are divisible by <code><var>GCD</var></code>.</p>
 						<p data-if="GCD > 1 && (A*F-D*C) < 0">Divide by the common factor and swap signs so the denominator isn't negative.</p>
 						<p data-else-if="GCD > 1">Divide by the common factor.</p>
 						<p data-else>Swap signs so the denominator isn't negative.</p>
@@ -312,4 +312,4 @@
 		</div>
 	</div>
 </body>
-</html>
+</html>

khan-exercise.js

@@ -36,7 +36,10 @@ var primes = [2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43,
 	},
 
 	// Check to see if we're in test mode
-	testMode = (window.location.host.indexOf("localhost") === 0 || window.location.protocol === "file:") && /\.html$/.test( window.location.pathname ),
+	testMode = (window.location.host.indexOf("localhost") === 0 ||
+				window.location.host.indexOf("127.0.0.1") === 0 ||
+				window.location.protocol === "file:") &&
+				/\.html$/.test( window.location.pathname ),
 
 	// Check to see if we're in beta mode
 	betaMode = window.location.host.indexOf( "khan-masterslave" ) !== -1,