Use below code.
HTML
<link rel="stylesheet" href="https://ajax.googleapis.com/ajax/libs/jqueryui/1.11.4/themes/smoothness/jquery-ui.css" />
<script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js"></script>
<script type="text/javascript" src="https://ajax.aspnetcdn.com/ajax/jquery.ui/1.11.4/jquery-ui.js"></script>
<link href="https://mottie.github.io/Keyboard/css/keyboard.css" rel="stylesheet" />
<script type="text/javascript" src="https://mottie.github.io/Keyboard/js/jquery.keyboard.js"></script>
<script type="text/javascript">
$(function () {
$('[id*=num]').keyboard({
layout: 'custom',
autoAccept: 'true',
maxLength: 10,
customLayout: {
'default': [
'7 8 9',
'4 5 6',
'1 2 3',
'0 {bksp}'
]
}
})
});
</script>
<div id="page-wrap">
<div class="block">
Mobile Number :
<asp:TextBox runat="server" ID="num" />
</div>
</div>