diff --git a/fx_s2308_double.c b/fx_s2308_double.c
index d5f5b475b96a9b21c7808488f4fd355b2b691135..e757dafeee14403b3c70b3aa7aa62b2a71f4f816 100644
--- a/fx_s2308_double.c
+++ b/fx_s2308_double.c
@@ -1,19 +1,18 @@
 #include "fx_s2308_double.h"
 #include <math.h>
 
-#define PI 3.1415926535897
 #define TO_RADIAN(a) (a*(PI/180))
 
-fx_s2308 fx_sine(fx_s2308 a){
+fx_s2308 fx_s2308_double_sine(fx_s2308 a){
 	double f_a=FX_TO_DOUBLE(a);
 	f_a=TO_RADIAN(f_a);
 	return DOUBLE_TO_FX(sin(f_a));
 }
-fx_s2308 fx_sqrt(fx_s2308 a){
+fx_s2308 fx_s2308_double_sqrt(fx_s2308 a){
 	double f_a=FX_TO_DOUBLE(a);
 	return DOUBLE_TO_FX(sqrt(f_a));
 }
-fx_s2308 fx_pow(fx_s2308 a, double n){
+fx_s2308 fx_s2308_double_pow(fx_s2308 a, double n){
 	double f_a=FX_TO_DOUBLE(a);
 	return DOUBLE_TO_FX(pow(f_a,n));
 }
diff --git a/fx_s2308_double.h b/fx_s2308_double.h
index 237238460d3ebad233e829d25f6e9a9ded98637a..175a54098f480f7f07e9233398b6f94839f5cf49 100644
--- a/fx_s2308_double.h
+++ b/fx_s2308_double.h
@@ -4,15 +4,16 @@ typedef double fx_s2308;
 #define FX_TO_FLOAT(a) ((float) (a/(256.0)))
 #define FX_TO_INT(a) ((int) (a/(256.0)))
 #define FX_TO_SHORT(a) ((short) (a/(256.0)))
-#define DOUBLE_TO_FX(a) (((int)(a*(256.0))))
+#define DOUBLE_TO_FX(a) (((double)(a*(256.0))))
 #define FX_ADD(a,b) ((a)+(b))
 #define FX_SUB(a,b) ((a)-(b))
 #define FX_MUL(a,b) DOUBLE_TO_FX(FX_TO_DOUBLE(a)*FX_TO_DOUBLE(b))
 #define FX_DIV(a,b) DOUBLE_TO_FX(FX_TO_DOUBLE(a)/FX_TO_DOUBLE(b))
 #define PI 3.141592
-#define FX_PI (INT_TO_FX(PI))
+#define FX_PI (DOUBLE_TO_FX(PI))
+#define FX_INV_PI (DOUBLE_TO_FX(1/PI))
 
-fx_s2308 fx_sine(fx_s2308 a);
-fx_s2308 fx_sqrt(fx_s2308 a);
-fx_s2308 fx_pow(fx_s2308 a, double n);
 
+fx_s2308 fx_s2308_double_sine(fx_s2308 a);
+fx_s2308 fx_s2308_double_sqrt(fx_s2308 a);
+fx_s2308 fx_s2308_double_pow(fx_s2308 a, double n);
\ No newline at end of file
diff --git a/test.c b/test.c
index 8fdf999aa16921aeec9159edc557021cb1fa73a6..04b053c8372dde4e2f69aa62c1c44ad7da1b9e04 100644
--- a/test.c
+++ b/test.c
@@ -7,25 +7,45 @@ int main() {
 	fx_s2308 output = FX_MUL(a, b);
 	printf("%lf\n",output);
 	
-	printf("===sine test===\n");
+	printf("\n===Calculation: Addition===\n");
+	printf("%f + %f = %f\n",a,b,FX_ADD(a,b));
+	printf("\n===Calculation: Subtraction===\n");
+	printf("%f - %lf = %f\n",a,b,FX_SUB(a,b));
+	printf("\n===Calculation: Multiplication===\n");
+	printf("%f * %lf = %f\n",a,b,FX_MUL(a,b));
+	printf("\n===Calculation: Division===\n");
+	printf("%f / %lf = %f\n",a,b,FX_DIV(a,b));
+
+	printf("\n===Function: Sine===\n");
 	double a1=30.0;
 	fx_s2308 f_a1=DOUBLE_TO_FX(a1);
-	fx_s2308 sine_a1=fx_sine(f_a1);
-	printf("%lf %lf %lf\n",a1,f_a1,FX_TO_DOUBLE(sine_a1));
+	fx_s2308 sine_a1=fx_s2308_double_sine(f_a1);
+	printf("sine(%lf)의 fx_2308 값: %lf, Double로 변환: %lf\n",a1,f_a1,FX_TO_DOUBLE(sine_a1));
 
-	printf("===sqrt test===\n");
+	printf("\n===Function: Sqrt===\n");
 	double a2=100.0;
 	fx_s2308 f_a2=DOUBLE_TO_FX(a2);
-	fx_s2308 sqrt_a2=fx_sqrt(f_a2);
-	printf("%lf %lf %lf\n",a2,f_a2,FX_TO_DOUBLE(sqrt_a2));
-	
-	printf("===power test===\n");
+	fx_s2308 sqrt_a2=fx_s2308_double_sqrt(f_a2);
+	printf("sqrt(%lf)의 fx_2308 값: %lf, Double로 변환: %lf\n",a2,f_a2,FX_TO_DOUBLE(sqrt_a2));
+	printf("\n===Function: Power===\n");
 	double a3=64.0;
 	fx_s2308 f_a3=DOUBLE_TO_FX(a3);
-	fx_s2308 pow_a3=fx_pow(f_a3,2.0);
-	printf("%lf %lf %lf\n",a3,f_a3,FX_TO_DOUBLE(pow_a3));
-	
+	fx_s2308 pow_a3=fx_s2308_double_pow(f_a3,2.0);
+	printf("%lf의 2.0 제곱의 fx_2308 값: %lf, Double로 변환: %lf\n",a3,f_a3,FX_TO_DOUBLE(pow_a3));
+
+	printf("\n===Conversion: fx to double===\n");
+	printf("fx_s2308 %lf is changed into double %lf\n", a, FX_TO_DOUBLE(a));
+	printf("\n===Conversion: fx to float===\n");
+	printf("fx_s2308 %lf is changed into float %f\n", a, FX_TO_FLOAT(a));
+	printf("\n===Conversion: fx to int===\n");
+	printf("fx_s2308 %lf is changed into double %d\n", a, FX_TO_INT(a));
+	printf("\n===Conversion: fx to short===\n");
+	printf("fx_s2308 %lf is changed into double %d\n", a, FX_TO_SHORT(a));
 
+	printf("\n===Constant: PI===\n");
+	printf("PI의 fx_2308 값: %lf\n",FX_PI);
+	printf("\n===Constant: Inverse PI===\n");
+	printf("1/PI의 fx_2308 값: %lf\n",FX_INV_PI);
 
 	return 0;
 }