diff --git a/homework/calculate/calculate.hpp b/homework/calculate/calculate.hpp
index 7a933a25..8908346f 100644
--- a/homework/calculate/calculate.hpp
+++ b/homework/calculate/calculate.hpp
@@ -2,6 +2,30 @@
 #include <string>
 
 std::string calculate(const std::string& command, int first, int second) {
-    // TODO: Implement your solution here and return proper value
-    return "";
+    int result = 0;
+    if (command == "add") {
+        result = first + second;
+    }
+
+    else if (command == "subtract") {
+        result = first - second;
+    }
+
+    else if (command == "multiply") {
+        result = first * second;
+    }
+
+    else if (command == "divide") {
+        if (second == 0) {
+            return "Division by 0";
+        }
+
+        result = first / second;
+    }
+
+    else {
+        return "Invalid data";
+    }
+
+    return std::to_string(result);
 }