The new awesome way to include math in a website is MathJax. Until recently, one had to install MathJax in their own server in order to include math in their webpages. That changed a few weeks ago; you can now specify in your html code that the required script be loaded from MathJax's website. To get MathJax to work in Blogger, just go to your Blogger account, click "Design" (top right of the page