diff --git a/scripts/test_sum/test_sum.c b/scripts/test_sum/test_sum.c
new file mode 100644
index 0000000..1aad36c
--- /dev/null
+++ b/scripts/test_sum/test_sum.c
@@ -0,0 +1,22 @@
+#include <stdio.h>
+
+//functions be local in C
+int sum(int n) {
+	if (n < 2) {
+		return n;
+	}
+
+	return n + sum(n - 1);
+}
+
+//the test case (C)
+void test_sum(int key, int val) {
+	const int result = sum(val);
+	printf("%d: %d\n", key, result);
+}
+
+int main() {
+	for (int i = 0; i <= 10; i++) {
+		test_sum(i, i * 1000);
+	}
+}
\ No newline at end of file
diff --git a/scripts/test_sum.js b/scripts/test_sum/test_sum.js
similarity index 100%
rename from scripts/test_sum.js
rename to scripts/test_sum/test_sum.js
diff --git a/scripts/test_sum.toy b/scripts/test_sum/test_sum.toy
similarity index 100%
rename from scripts/test_sum.toy
rename to scripts/test_sum/test_sum.toy