Demo
1. Login to your Blogger Dashboard, and navigate to Design > Edit HTML.
2. Click on the checkbox which says “Expand Widget Templates”
3. Look for <data:post.body/> and immediately below that paste the following code.
<div>
<b:if cond='data:post.isFirstPost'>
<script>(function(d){
var js, id = 'facebook-jssdk'; if (d.getElementById(id)) {return;}
js = d.createElement('script'); js.id = id; js.async = true;
js.src = "//connect.facebook.net/en_US/all.js#xfbml=1";
d.getElementsByTagName('head')[0].appendChild(js);
}(document));</script>
</b:if>
<fb:send expr:href="data:post.canonicalUrl" font="arial" colorscheme="light"></fb:send>
</div>