Is a Double Degree equivalent to 2 single degrees? I want to study Bachelor of Mathematics at university in Australia. While I was surfing the various courses, I came across something interesting. It was Bachelor of Mathematics and Bachelor of Computer Science at University pf Wollongong (which takes 4.5 years to complete). I was like wow how does this work, Same qualification, and two degrees for 4.5 years. A single degree alone takes 4 years. But then I started to think, wait a minute this seems too good to be true. 

(Note that my intention is to study Mathematics and do a PhD in Mathematics, I don't want to get some limited mathematics knowledge if double degree has half of both. At the same time I would love if this is full of both, so in that case I will apply to this.

Please help me on how this works , what are the limitations, will I get the same recognition and knowledge as students studying Math alone?
I took a double degree in Electronic Engineering and IT (Computer Science) from QUT. It required more time than either of the single degrees, and the course load was considerably higher per semester. At graduation, I received two separate degree certificates from QUT — I have two Bachelor degrees. There were some restrictions in the number of elective subjects we could take, since the core course load was higher.

Of course you need to check the course content and course load (and duration — a Bachelors degree without honours in Australia is usually three years, not four), to be certain it's right for you.