diff --git a/du3/program.c b/du3/program.c
index 1a4a2de..c9fce20 100644
--- a/du3/program.c
+++ b/du3/program.c
@@ -1,6 +1,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <math.h>
 
 float plus(float total, float number);
 float minus(float total, float number);
@@ -86,6 +87,7 @@ int main() {
 			}
 			sign = !sign;	
 		}
+		memset(equation, 0, sizeof(equation));
 		//printf("%s\n",out);
 
 	}