How to select all text in Winforms NumericUpDown upon tab in?

private void NumericUpDown1_Enter(object sender, EventArgs e)
{
    NumericUpDown1.Select(0, NumericUpDown1.Text.Length);
}

(Note that the Text property is hidden in Intellisense, but it's there)

For selecting all text by mouse click or by Tab button I use:

    public frmMain() {
        InitializeComponent();
        numericUpDown1.Enter += numericUpDown_SelectAll;
        numericUpDown1.MouseUp += numericUpDown_SelectAll;
    }

    private void numericUpDown_SelectAll(object sender, EventArgs e) {
        NumericUpDown box = sender as NumericUpDown;
        box.Select(0, box.Value.ToString().Length);
    }