diff --git a/README.md b/README.md
index 30ed37427b23d8fc6c5d208757cf9ca11fc27ba7..c601fa44f88deba92a9f33abcb1c295dc7c3a04f 100644
--- a/README.md
+++ b/README.md
@@ -309,45 +309,38 @@ DIV_03의 경우 오차율이 조금 증가하지만 범용적으로 사용할 
 <br>
 
 ### 속도 테스트
+
 ![image](images/speed-experiment.png)
+
 * 32bit 실행 결과
 
 1. Multiply
 
-    MUL_03 < MUL_02 < MUL_01
-
-<br>
+    MUL_03 = MUL_02 < MUL_01
 
-32 bit에서 곱셈을 실행한 결과, cast하지 않은 것들에서 빠른 성능을 보인다는 것을 알 수 있었다.
 
-<br>
-<br>
 
 2. Division    
 
-    DIV_01 = DIV_03 < DIV_02
+    DIV_03 < DIV_02 < DIV_01
 
 
-<br>
 <br>
 
 * 64bit 실행 결과
 1. Multiply     
 
-    MUL_03 = MUL_02 < MUL_01
+    MUL_03 < MUL_02 < MUL_01
 
 
-<br>
-<br>
 
 2. Division      
 
-    DIV_02 < DIV_03 < DIV_01
+    DIV_01 = DIV_02 < DIV_03
 
 <br>
 <br>
 
-
 ### Sin
 
 #### sin table
@@ -390,6 +383,67 @@ fx_1516_SinTable은 fx_s1516에 맞춰진 표이므로, fx_s1615에 맞춰 변
 <br>
 <br>
 
+
+
+### double vs long long
+
+* double 과 long long으로 형변환을 하여 곱셈 및 나눗셈을 수행할 때, 어떤 것이 더 빠른지 측정해보았다.
+
+1. multiple test
+
+ 
+ ```
+Flat profile:
+
+Each sample counts as 0.01 seconds.
+  %   cumulative   self              self     total           
+ time   seconds   seconds    calls   s/call   s/call  name    
+ 63.43      2.00     2.00        1     2.00     2.00  fx_1615_double_mul_test
+ 12.69      2.41     0.40        1     0.40     0.40  fx_1615_longlong_mul1_test
+ 12.05      2.79     0.38        1     0.38     0.38  fx_1615_longlong_mul2_test
+ 12.05      3.17     0.38        1     0.38     0.38  fx_1615_longlong_mul3_test
+
+			Call graph
+
+
+granularity: each sample hit covers 2 byte(s) for 0.32% of 3.17 seconds
+
+index % time    self  children    called     name
+                                                 <spontaneous>
+[1]    100.0    0.00    3.17                 main [1]
+                2.00    0.00       1/1           fx_1615_double_mul_test [2]
+                0.40    0.00       1/1           fx_1615_longlong_mul1_test [3]
+                0.38    0.00       1/1           fx_1615_longlong_mul3_test [5]
+                0.38    0.00       1/1           fx_1615_longlong_mul2_test [4]
+-----------------------------------------------
+                2.00    0.00       1/1           main [1]
+[2]     63.3    2.00    0.00       1         fx_1615_double_mul_test [2]
+-----------------------------------------------
+                0.40    0.00       1/1           main [1]
+[3]     12.7    0.40    0.00       1         fx_1615_longlong_mul1_test [3]
+-----------------------------------------------
+                0.38    0.00       1/1           main [1]
+[4]     12.0    0.38    0.00       1         fx_1615_longlong_mul2_test [4]
+-----------------------------------------------
+                0.38    0.00       1/1           main [1]
+[5]     12.0    0.38    0.00       1         fx_1615_longlong_mul3_test [5]
+-----------------------------------------------
+
+Index by function name
+
+   [2] fx_1615_double_mul_test [4] fx_1615_longlong_mul2_test
+   [3] fx_1615_longlong_mul1_test [5] fx_1615_longlong_mul3_test
+
+ ```
+
+[실행 결과 정리]
+* double이 long long으로 곱셈을 실행하는 것 보다 더 많은 시간이 소요된다는 것을 알 수 있었다.
+* fx_s1615로 표현된 값인 a를 8만큼 right shifting 해주고, b를 7만큼 right shifiting 해준 후, 두 값을 곱해주는 fx_1615_longlong_mul3_test의 실행속도가 가장 빠른 것을 알 수 있었다.
+
+<br>
+<br>
+
+
 ## 0819 과제
 
 ### 요구사항 명세
diff --git a/multipleOutput.txt b/multipleOutput.txt
index dbde321dc734230a46d48c3bdd520a7ea70c4bb0..fd2989454c5a9ce16619f17fe87ef8e78df1f2d9 100644
--- a/multipleOutput.txt
+++ b/multipleOutput.txt
@@ -3,38 +3,38 @@ Flat profile:
 Each sample counts as 0.01 seconds.
   %   cumulative   self              self     total           
  time   seconds   seconds    calls   s/call   s/call  name    
- 42.53      2.13     2.13        1     2.13     2.13  fx_1615_double_test
- 33.54      3.82     1.68        1     1.68     1.68  fx_1615_longlong_div03_test
- 11.98      4.42     0.60        1     0.60     0.60  fx_1615_longlong_div01_test
- 11.58      5.00     0.58        1     0.58     0.58  fx_1615_longlong_div02_test
+ 63.43      2.00     2.00        1     2.00     2.00  fx_1615_double_mul_test
+ 12.69      2.41     0.40        1     0.40     0.40  fx_1615_longlong_mul1_test
+ 12.05      2.79     0.38        1     0.38     0.38  fx_1615_longlong_mul2_test
+ 12.05      3.17     0.38        1     0.38     0.38  fx_1615_longlong_mul3_test
 
 			Call graph
 
 
-granularity: each sample hit covers 2 byte(s) for 0.20% of 5.00 seconds
+granularity: each sample hit covers 2 byte(s) for 0.32% of 3.17 seconds
 
 index % time    self  children    called     name
                                                  <spontaneous>
-[1]    100.0    0.00    5.00                 main [1]
-                2.13    0.00       1/1           fx_1615_double_test [2]
-                1.68    0.00       1/1           fx_1615_longlong_div03_test [3]
-                0.60    0.00       1/1           fx_1615_longlong_div01_test [4]
-                0.58    0.00       1/1           fx_1615_longlong_div02_test [5]
+[1]    100.0    0.00    3.17                 main [1]
+                2.00    0.00       1/1           fx_1615_double_mul_test [2]
+                0.40    0.00       1/1           fx_1615_longlong_mul1_test [3]
+                0.38    0.00       1/1           fx_1615_longlong_mul3_test [5]
+                0.38    0.00       1/1           fx_1615_longlong_mul2_test [4]
 -----------------------------------------------
-                2.13    0.00       1/1           main [1]
-[2]     42.7    2.13    0.00       1         fx_1615_double_test [2]
+                2.00    0.00       1/1           main [1]
+[2]     63.3    2.00    0.00       1         fx_1615_double_mul_test [2]
 -----------------------------------------------
-                1.68    0.00       1/1           main [1]
-[3]     33.7    1.68    0.00       1         fx_1615_longlong_div03_test [3]
+                0.40    0.00       1/1           main [1]
+[3]     12.7    0.40    0.00       1         fx_1615_longlong_mul1_test [3]
 -----------------------------------------------
-                0.60    0.00       1/1           main [1]
-[4]     12.0    0.60    0.00       1         fx_1615_longlong_div01_test [4]
+                0.38    0.00       1/1           main [1]
+[4]     12.0    0.38    0.00       1         fx_1615_longlong_mul2_test [4]
 -----------------------------------------------
-                0.58    0.00       1/1           main [1]
-[5]     11.6    0.58    0.00       1         fx_1615_longlong_div02_test [5]
+                0.38    0.00       1/1           main [1]
+[5]     12.0    0.38    0.00       1         fx_1615_longlong_mul3_test [5]
 -----------------------------------------------
 
 Index by function name
 
-   [2] fx_1615_double_test     [5] fx_1615_longlong_div02_test
-   [4] fx_1615_longlong_div01_test [3] fx_1615_longlong_div03_test
+   [2] fx_1615_double_mul_test [4] fx_1615_longlong_mul2_test
+   [3] fx_1615_longlong_mul1_test [5] fx_1615_longlong_mul3_test