diff --git a/README.md b/README.md
index a09b6e2..200d658 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,4 @@
 # Step-1-Code
 This repo is for your first open source contribution! Just add some beginner projects and complete your Hacktoberfest 2020 challenge.
+# Step-2-Test and debug
+Testing is the process to find bugs and error and debugging is the process to correct the bugs found during testing.
diff --git a/calculator using C programming b/calculator using C programming
new file mode 100644
index 0000000..806bfff
--- /dev/null
+++ b/calculator using C programming	
@@ -0,0 +1,36 @@
+#include<stdio.h>
+#include<math.h>
+
+main()
+{
+float a,b,c, result;
+printf("enter the numbers and the operation.");
+scanf("%d %d" %d, &a,&b,&c);
+printf("select operation");
+switch (c)
+{
+case 1:
+     return a+b;
+     break;
+case 2:
+     return a-b;
+     break;
+case 3:
+     return a*b;
+     break;
+case 4:
+     return a/b;
+     break;
+case 5:
+     return pow(a,b)
+     break;
+case 6:
+     return sqrt(a);
+     break;
+case 7: 
+      return log(a);
+      break;
+}
+printf("result = %d", result);
+return 0;
+}