No but 52.14 times 149.50 does, near as dammit!crashuk said:149.50 , 52 times dosent not equal to £7800.
I think the root of your problem is this mythical "£150 a week". The contract obviously states £7800 per annum or £650 per month, which are obviously the same thing. This equates to approximately £149.50 per week, NOT £150, but someone has obviously just called it "150 quid" for ease.
Leaving leap years out of it for simplicity and assuming 365 day years, you are paid £7800 per year or £650 per month or £21.37 per day. Can you at least see how this is worked out? 7800/12=650, 7800/365=21.37.
If you are paid £21.37 per day then you are paid £149.59 per week (21.37x7=149.59).
There are approximately 52.14286 weeks in a year. £149.59 x 52.14286 = £7800.05 per year.
Where is the problem here!?