We don't have dollars. That little £ sign means pounds, as in Pounds Sterling or GBP (United Kingdom Pounds) which is our unit of currency. It's actually an L sign with a stroke through it. It doesn't stand for England but is from "Librum" which means pound (as in weight) in Latin. You have dollars and cents, we have pounds and pence. The signs are £=pounds and p=pence. There are 100 pence in 1 pound. Sometimes we pronounce the p for pence as pee - I know that is funny!
So if someone says it costs five pounds two pee, you will know what they mean.
Some other weird words are used in the UK for particular coins or notes. A fiver=£5, a tenner=£10, two bob = 20p, one bob=10p, a shilling=5p, a penny=1p

£42 = $77.75