diff --git a/day6/case1.cpp b/day6/case1.cpp
new file mode 100644
index 0000000..9f82bac
--- /dev/null
+++ b/day6/case1.cpp
@@ -0,0 +1,15 @@
+// 案例1: data 为 1 字节 将 data 的第 3, 4 位清 0 其他位保持不变
+#include <iostream>
+#include <bitset>
+
+using namespace std;
+
+int main()
+{
+    char n = 0b01011011; // 0x5b = 0101 1011
+    cout << "原值: " << bitset<8>(n) << endl;
+    // 1000 | 10000 = 0001 1000  ; ~00011000 = 11100111
+    n &= ~(0x1 << 3 | 0x1 << 4);
+    cout << "结果: " << bitset<8>(n) << endl;
+    return 0;
+}
\ No newline at end of file
diff --git a/day6/case2.cpp b/day6/case2.cpp
new file mode 100644
index 0000000..456be4a
--- /dev/null
+++ b/day6/case2.cpp
@@ -0,0 +1,16 @@
+// 案例2: data 为 1 字节, 将 data 的第 5, 6 为置 1 其他位保持不变
+#include <iostream>
+#include <bitset>
+
+using namespace std;
+
+int main()
+{
+    char n = 0b10001011; // 0x8b = 1000 1011
+    cout << "原值: " << bitset<8>(n) << endl;
+
+    // 1000 | 10000 = 0001 1000
+    n |= (0x1 << 5 | 0x1 << 6); // 将第 5, 6 位置为 1
+    cout << "结果: " << bitset<8>(n) << endl;
+    return 0;
+}
\ No newline at end of file
diff --git a/day6/case3.cpp b/day6/case3.cpp
new file mode 100644
index 0000000..aa75cea
--- /dev/null
+++ b/day6/case3.cpp
@@ -0,0 +1,15 @@
+// 案例3: data 为 1 字节, 将 data 的第 3, 4 位清0, 5, 6 置 1 其他位保持不变
+#include <iostream>
+#include <bitset>
+
+using namespace std;
+
+int main()
+{
+    char data = 0b10011011;
+    cout << "原值: " << bitset<8>(data) << endl;
+
+    data = (data & ~(0x1 << 3 | 0x1 << 4)) | (0x1 << 5 | 0x1 << 6);
+    cout << "结果: " << bitset<8>(data) << endl;
+    return 0;
+}
\ No newline at end of file