Although it is recommended you come in with knowledge equivalent to 2 unit maths, it isn't necessary. It also depends on the majors you want to do as as well. Econ and Finance are considered the more mathematically complex and intensive. Accounting is more arithmetic based I guess than Econ and Finance while all the other majors barely touch any high level maths.
In all honesty, I've known people who only did general maths and did quite well (distinction average +) in the economics major. The university does offer introductory maths subjects in the econ and finance major. They also offer bridging courses if I'm not mistaken. As nerdasdasd has said, if you apply yourself you shouldn't have a problem.
If it is even worth anything, I did do 3 unit maths in high school but by the time I got to econ subjects I had forgotten quite a lot of my high school maths. The intro maths subjects if I remember correctly did go through almost everything from the basics, at least for calculus. So I would say first year business with little math knowledge is fine. All it matters is the major you do but there are plenty of resources in the university to help you out if needed.