diff --git a/calculator/calculator_test.go b/calculator/calculator_test.go
new file mode 100644
index 0000000..f4e3ab4
--- /dev/null
+++ b/calculator/calculator_test.go
@@ -0,0 +1,9 @@
+package calculator
+
+import "testing"
+
+func TestAdd(t *testing.T) {
+	if got, want := Add(1, 2), 3; got != want {
+		t.Errorf("add method produced wrong result. expected: %d, got: %d", want, got)
+	}
+}