Writing Tutorial - Formatting issues

I'm writing a math heavy tutorial which requires me to use the plus (+) and times/multiply (*) symbols, however since they are also being used as formatting marks (bold and italic) when I preview it's parcing these as attempts to format text.

Needless to say, hilarity is ensuing. Tom is there a work around for this?

Wrap square brackets around the asterix:

[ * ] (but no spaces)

And it will come out as an asterix. Shouldn't be any problems with plus sign, can you give me an example?

https://www.scirra.com/tutorials/487/using-physics-objects-momentum-to-assign-damage

Looks like the issue with the plus sign is only in the preview. Shows up ok in the code view. There's some minor wonkieness in the second equation where I used the code formatting, but otherwise everything looks like it works. Thanks for the workaround with the asterix!