<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:gravity="center"
        tools:ignore="UselessParent">

        <NumberPicker
            android:id="@+id/number_picker"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content">

        </NumberPicker>

    </LinearLayout>

</LinearLayout>