subtraction yes no determination

2 files changed, 25 insertions, 5 deletions

diff --git a/4.N.10_Parser.php b/4.N.10_Parser.php
index 2900d83..d36f07a 100644
--- a/4.N.10_Parser.php
+++ b/4.N.10_Parser.php
@@ -176,18 +176,31 @@ foreach ($Class as $student)
 {
 	if( $num_correct[$student] >= ( .7 * ($num_submissions))
 	{
-		$understands_addition = "yes"
+		$understands_addition = true;
 	}
 	else
 	{
-		$understands_addition = "no"
+		$understands_addition = false;
 	}
 
 
 //*************Subtraction Yes/No *************
 
 	
-		if($subtraction_correct[$student] >= .10 * $ 
+		if($incorrect_subtraction[$student] / $correct_subtraction[$student] <= .10)
+		{
+			$understands_subtraction = "y"; //we cannot use bool as there is a third case of "undetermined" with subtraction. 
+		}
+		elseif($incorrect_subtraction[$student] == NULL || $incorrect_subtraction[$student] == 0)
+		{
+			$understands_subtraction = "u"
+		}
+		else
+		{
+			$understands_subtraction = "n"
+		}
+
+
 	
 } //end foreach
 			
diff --git a/4.N.10_Parser.php~ b/4.N.10_Parser.php~
index 4d7c6ba..2900d83 100644
--- a/4.N.10_Parser.php~
+++ b/4.N.10_Parser.php~
@@ -95,7 +95,7 @@ for (i=0;i<=$numRecords;i++)
 						//determine subtraction
 						if ($previous_response[$question_id] == "o") // if you previously overpaid
 						{
-							$correct_subtraction[$student_id]++;							
+							$correct_subtraction[$student_id]++;	//The amount of times a student invoked subtractions correctly						
 						}
 
 
@@ -124,6 +124,7 @@ for (i=0;i<=$numRecords;i++)
 						elseif($previous_response[$question_id] == "o")
 						{
 							$strikes[$student_id]++;
+							$incorrect_subtraction[$student_id]
 						}	 				
 		 			} 
 
@@ -148,6 +149,7 @@ for (i=0;i<=$numRecords;i++)
 						}
 						elseif($previous_response[$question_id] == "o")
 						{
+							$incorrect_subtraction[$student_id]++;
 						}
 						
 	
@@ -180,7 +182,12 @@ foreach ($Class as $student)
 	{
 		$understands_addition = "no"
 	}
-		
+
+
+//*************Subtraction Yes/No *************
+
+	
+		if($subtraction_correct[$student] >= .10 * $ 
 	
 } //end foreach