java Fx

<?xml version="1.0" encoding="UTF-8"?>

<?import javafx.geometry.*?>
<?import javafx.scene.control.*?>
<?import javafx.scene.layout.*?>


<VBox alignment="CENTER" spacing="10.0" xmlns="http://javafx.com/javafx/10.0.2-internal" xmlns:fx="http://javafx.com/fxml/1" fx:controller="sample.Controller">
   <children>
      <Label id="label_top" fx:id="ans" alignment="TOP_LEFT" text="0" />
      <Label id="label_top" fx:id="ans1" alignment="TOP_LEFT" layoutX="134.0" layoutY="10.0" text="______________________" />
      <VBox alignment="CENTER" spacing="10.0">
         <children>
            <HBox alignment="CENTER" spacing="5.0">
               <children>
                  <Button id="btn-1" mnemonicParsing="false" onAction="#pressNum" text="1" />
                  <Button id="btn-2" mnemonicParsing="false" onAction="#pressNum" text="2" />
                  <Button id="btn-3" mnemonicParsing="false" onAction="#pressNum" text="3" />
                  <Button id="btn-a-1" mnemonicParsing="false" onAction="#pressAct" text="/" />
               </children>
            </HBox>
            <HBox alignment="CENTER" spacing="5.0">
               <children>
                  <Button id="btn-4" mnemonicParsing="false" onAction="#pressNum" text="4" />
                  <Button id="btn-5" mnemonicParsing="false" onAction="#pressNum" text="5" />
                  <Button id="btn-6" mnemonicParsing="false" onAction="#pressNum" text="6" />
                  <Button id="btn-a-2" mnemonicParsing="false" onAction="#pressAct" text="*" />
               </children>
            </HBox>
            <HBox alignment="CENTER" spacing="5.0">
               <children>
                  <Button id="btn-7" mnemonicParsing="false" onAction="#pressNum" text="7" />
                  <Button id="btn-8" mnemonicParsing="false" onAction="#pressNum" text="8" />
                  <Button id="btn-9" mnemonicParsing="false" onAction="#pressNum" text="9" />
                  <Button id="btn-a-3" mnemonicParsing="false" onAction="#pressAct" text="-" />
               </children>
            </HBox>
            <HBox alignment="CENTER" spacing="5.0">
               <children>
                  <Button id="btn-0" mnemonicParsing="false" onAction="#pressNum" text="0" />
                  <Button id="btn-c" mnemonicParsing="false" onAction="#clearAll" text="C" />
                  <Button id="btn-dot" mnemonicParsing="false" onAction="#pressNum" text="." />
                  <Button id="btn-a-4" mnemonicParsing="false" onAction="#pressAct" text="+" />
               </children>
            </HBox>
         </children>
      </VBox>
      <Button id="btn_a_5" alignment="CENTER" mnemonicParsing="false" onAction="#pressEqual" prefHeight="25.0" prefWidth="104.0" text="=" textAlignment="CENTER" />
      <Label text="Simple JavaFX Calculator created by Milton" />
   </children>
   <padding>
      <Insets bottom="10.0" left="10.0" right="10.0" top="10.0" />
   </padding>
</VBox>