Create Read More... for Classic Template

Sign in blogger.com and click layout.. Click edit HTML
Next...

• Copy This code on the </style>
• <MainOrArchivePage>
  
  div.fullpost {display:none;}
  
  </MainOrArchivePage>
  
  <ItemPage>
  
  div.fullpost {display:inline;}
  
  </ItemPage>
• Copy and paste this code after <$BlogItemBody$> <MainOrArchivePage><br/>
  
  <a href="<$BlogItemPermalinkURL$>">Read more!</a>
  
  </MainOrArchivePage>
• Clicks Setting choose Formatting copy and paste this code in box Post Template <div class="fullpost">
  
  
  </div>
• Click Save Settings.
• Finish

You can try in your blog.. ist easy you know that..!!!