diff --git a/programs/C/calculator.c b/programs/C/calculator.c
new file mode 100644
index 0000000..a21d250
--- /dev/null
+++ b/programs/C/calculator.c
@@ -0,0 +1,63 @@
+// add a program for a calculator(+, -, *, /) in C
+#include<stdio.h>
+void Input(){
+printf("Type number to choose the algorithm\n");
+printf( " 1. + \n 2. - \n 3. *\n 4. / \n 5.Exit\n InputNum: ");
+}
+ int main()
+{
+   int InputNum=0;
+   float a=0;
+   float b=0;
+   float result=0;
+ do{
+    Input();
+    scanf("%d", &InputNum);
+    switch(InputNum){
+   case(1):
+       printf("Enter First Number: ");
+       scanf("%f", &a);
+       printf("Enter Second Number: ");
+       scanf("%f", &b);
+       result = a + b;
+       printf("%.2f + %.2f = %.2f\n",a , b, result);
+       break;
+   case(2):
+       printf("Enter First Number: ");
+       scanf("%f", &a);
+       printf("Enter Second Number: ");
+       scanf("%f", &b);
+       result = a - b;
+       printf("%.2f - %.2f = %.2f\n",a ,b, result);
+       break;
+   case(3):
+       printf("Enter First Number: ");
+       scanf("%f", &a);
+       printf("Enter Second Number: ");
+       scanf("%f", &b);
+       result = a * b;
+       printf("%.2f * %.2f = %.2f\n",a ,b, result);
+       break;
+   case(4):
+       printf("Enter Dividend: ");
+       scanf("%f", &a);
+       printf("Enter Divisor: ");
+       scanf("%f", &b);
+       if (b == 0){
+            printf("Please check the divisor that can not be zero.\n");
+       }
+       else{
+           result = a / b;
+           printf("%.2f / %.2f = %.2f\n",a ,b, result);
+       }
+       break;
+   case(5):
+       printf("Thank you for using code !!\n");
+       break;
+    default:
+       printf("Invalid number, please choose again.\n");
+   }
+ }while(InputNum);
+   return 0;
+}
+