Yes, I'd echo that. I teach for a living, and it's amazing the number of different ways people can come up with when interpreting what you think is a straightf

Yes, I'd echo that. I teach for a living, and it's amazing the number of different ways people can come up with when interpreting what you think is a straightforward instruction. When I read the "delete lines ...." bit, it didn't seem completely explicit, and in addition, I'd think that alone would put a LOT of people off having a go. Much of this kind of thing is generating confidence in people, and if they fall at the first hurdle, it's game over; possibly for their entire lifetime if it happens at the wrong point!