I am studying Mathematical Computation at UCL. It is a joint maths and cs degree and in the first 2 years there is an equal balance of both maths and cs modules, but in second year you can choose to study 4 cs + 4 math or 5 cs + 3 math modules). In 3rd year (as of now) there is only one compulsory CS module, the other 7 are up to you to choose and can be either maths or cs modules. This change was introduced recently as before in 3rd year, 2 cs modules were compulsory. And in 4th year nothing is compulsory apart from the dissertation, which is worth 2 modules. So overall, the degree is ever so slightly towards the CS side but you are more than welcome to go into the maths side in later years. I guess this makes sense as the course is under the CS department, not the maths one. This unlike all of the other joint maths degrees at UCL, which are under the maths department. Hope that clears everything up.