diff --git a/【实践课内】1.顺序结构/7-1 计算摄氏温度.c b/【实践课内】1.顺序结构/7-1 计算摄氏温度.c
new file mode 100644
index 0000000..a94a5c9
--- /dev/null
+++ b/【实践课内】1.顺序结构/7-1 计算摄氏温度.c	
@@ -0,0 +1,11 @@
+#include <stdio.h>
+
+int main() {
+    int f;
+
+    scanf("%d", &f);
+
+    printf("Celsius = %d\n", 5 * (f - 32) / 9);
+
+    return 0;
+}
diff --git a/【实践课内】1.顺序结构/7-2 逆序的三位数.c b/【实践课内】1.顺序结构/7-2 逆序的三位数.c
new file mode 100644
index 0000000..493c050
--- /dev/null
+++ b/【实践课内】1.顺序结构/7-2 逆序的三位数.c	
@@ -0,0 +1,18 @@
+#include <stdio.h>
+
+int x;
+
+int main() {
+    scanf("%d", &x);
+
+    int res = 0;
+
+    while (x) {
+        res = (res * 10) + (x % 10);
+        x /= 10;
+    }
+
+    printf("%d\n", res);
+    
+    return 0;
+}
diff --git a/【实践课内】1.顺序结构/7-3 日期格式化.c b/【实践课内】1.顺序结构/7-3 日期格式化.c
new file mode 100644
index 0000000..89c2fce
--- /dev/null
+++ b/【实践课内】1.顺序结构/7-3 日期格式化.c	
@@ -0,0 +1,11 @@
+#include <stdio.h>
+
+int main() {
+    int y, m, d;
+
+    scanf("%2d-%2d-%4d", &m, &d, &y);
+
+    printf("%04d-%02d-%02d\n", y, m, d);
+
+    return 0;
+}
diff --git a/【实践课内】1.顺序结构/7-4 21-爬楼梯.c b/【实践课内】1.顺序结构/7-4 21-爬楼梯.c
new file mode 100644
index 0000000..777bb23
--- /dev/null
+++ b/【实践课内】1.顺序结构/7-4 21-爬楼梯.c	
@@ -0,0 +1,11 @@
+#include <stdio.h>
+
+int a, t, b;
+
+int main() {
+    scanf("%d%d%d", &a, &t, &b);
+
+    printf("%d", 1ll * t * (b - 1) / (a - 1));
+
+    return 0;
+}