We've just been given a calculator. You still want and should know how to do arithmetic without one, but it's much faster with it. The only trouble is, at the

We've just been given a calculator. You still want and should know how to do arithmetic without one, but it's much faster with it. The only trouble is, at the moment it makes subtle mistakes. So you really have to know what you're doing to use it properly. I reckon we're 6 months away from those mistakes becoming few and far between.