My Maths is pretty shoddy too but its never held me back and I'm a B2 by trade. Theres very little 'calculating' in our day to day work but whenever it is called for you can use a calculator
The only time you'll see a B2 guy using his calculator is when calculating how many hours sleep he's going to get on a night shift or how many replacement screws he'll need for an access panel after rounding them all off trying to remove it
