diff --git a/src/main/c/BasicMode.c b/src/main/c/BasicMode.c
index cabb5c4..a9ea1f8 100644
--- a/src/main/c/BasicMode.c
+++ b/src/main/c/BasicMode.c
@@ -65,40 +65,71 @@ long long int subtraction(long long int a, long long int b) {
 
 
 int main() {
-     long long int bin1, bin2, dec, result;
- char auswahl1, auswahl2;
-
- do {
-     printf("what do you want to do?(A for conversion from decimal base to binary base ,B for conversion from binary base to decimal base ,C for Operation in binary base, Q for stop):");
-     scanf(" %c", &auswahl1);
-      switch (auswahl1) {
- case 'A':
- case 'a':
-     printf("Enter a decimal number: ");
-     scanf("%lld", &dec);
-     bin1 = DecToBin(dec);
-     printf("%lld in decimal = %lld in binary\n", dec, bin1);
-     break;
-
- case 'B':
- case 'b':
-     printf("Enter a binary number: ");
-     scanf("%lld", &bin1);
-     dec = BinToDec(bin1);
-     printf("%lld in binary = %lld in decimalprintf\n");
-     break;
-
- case 'C':
- case 'c':
- do {
-    printf("which operation would you like to have?(+ for addition, - for subtraction,* for multiplication and r for return :");
-    scanf(" %c", &auswahl2);
-
-
-
+    long long int bin1, bin2, dec, result;
+    char auswahl1, auswahl2;
+
+    do {
+        printf("what do you want to do?(A for conversion from decimal base to binary base ,B for conversion from binary base to decimal base ,C for Operation in binary base, Q for stop):");
+        scanf(" %c", &auswahl1);
+        switch (auswahl1) {
+        case 'A':
+        case 'a':
+            printf("Enter a decimal number: ");
+            scanf("%lld", &dec);
+            bin1 = DecToBin(dec);
+            printf("%lld in decimal = %lld in binary\n", dec, bin1);
+            break;
 
+        case 'B':
+        case 'b':
+            printf("Enter a binary number: ");
+            scanf("%lld", &bin1);
+            dec = BinToDec(bin1);
+            printf("%lld in binary = %lld in decimalprintf\n");
+            break;
 
-  } while (auswahl2 != 'R' && auswahl2 != 'r');
+        case 'C':
+        case 'c':
+            do {
+                printf("which operation would you like to have?(+ for addition, - for subtraction,* for multiplication and r for return :");
+                scanf(" %c", &auswahl2);
+                switch (auswahl2) {
+                case '+':
+                    printf("enter the first binary number: ");
+                    scanf("%lld", &bin1);
+                    printf("enter the second binary number: ");
+                    scanf("%lld", &bin2);
+                    result = addition(bin1, bin2);
+
+                    printf("%lld+%d = %lld\n", bin1, bin2, result);
+                    break;
+                case '-':
+                    printf("enter the first binary number: ");
+                    scanf("%lld", &bin1);
+                    printf("enter the second binary number: ");
+                    scanf("%lld", &bin2);
+                    result = subtraction(bin1, bin2);
+
+                    printf("%lld-%lld = %lld\n", bin1, bin2, result);
+                    break;
+                case '*':
+                    printf("enter the first binary number: ");
+                    scanf("%lld", &bin1);
+                    printf("enter the second binary number: ");
+                    scanf("%lld", &bin2);
+                    result = multiplication(bin1, bin2);
+
+                    printf("%lld*%d = %lld\n", bin1, bin2, result);
+                    break;
+
+                case 'R':
+                case 'r':
+                    printf("return.\n");
+                    break;
+                default:
+                    printf("Invalid selection. Please enter again.\n");
+                }
+            } while (auswahl2 != 'R' && auswahl2 != 'r');
 
             break;
         case 'Q':
@@ -108,8 +139,8 @@ int main() {
         default:
             printf("Invalid selection. Please enter again.\n");
         }
+    } while (auswahl1 != 'Q' && auswahl1 != 'q');
 
 
- } while (auswahl1 != 'Q' && auswahl1 != 'q');
     return 0;
 }