Using the formula editor, how do i round up (or down) a number to x decimal places. eg:- I would like 1.239 rounded up to 2 decimal places to get the result 1.24. thanks!

Does anyone know how to remove a line break from a field?
I am trying to use MailingAddress in a hyperlink formula but it breaks every time there is a contact with a two line mailing address.

I have tried the following and they did not work:
substitute(MailingAddress,BR(),"")
substitute(MailingAddress,"\n","")
substitute(MailingAddress,\n,"")
trim(MailingAddress)

For reference my formula looks something like this:
hyperlink("http://linklocation.com?address="&MailingAddress,"Link Text", "_blank")