diff --git a/app/src/main/java/keijumt/devandroid/common/Calculate.kt b/app/src/main/java/keijumt/devandroid/common/Calculate.kt
deleted file mode 100644
index 58ec5f4..0000000
--- a/app/src/main/java/keijumt/devandroid/common/Calculate.kt
+++ /dev/null
@@ -1,34 +0,0 @@
-package keijumt.devandroid.common
-
-import android.os.AsyncTask
-
-class Calculate(val callback: Callback<Int>) : AsyncTask<Int, Int, Int>() {
-
-    // ui thread
-    override fun onPreExecute() {
-        println("onPreExecute")
-    }
-
-    override fun doInBackground(vararg params: Int?): Int {
-        try {
-            println("doInBackground")
-            Thread.sleep(3000)
-        } catch (e: Exception) {
-
-        }
-        val value = params.get(0) ?: 1
-        return value * value
-    }
-
-    override fun onProgressUpdate(vararg values: Int?) {
-        println("onPorgressUpdate")
-    }
-
-    override fun onPostExecute(result: Int?) {
-        callback.execute(result)
-    }
-
-    interface Callback<T> {
-        fun execute(value: T?)
-    }
-}
\ No newline at end of file