Too tired to think of one!

I'm exhausted after a 3 hour GSCE science lesson that still means the same amount to me as it did back in September... Nothing!!!  If anyone can explain how to change a word equation into something else and how and why to balance equations please step forward because i'm at a loss.Think i must feel like my poor class teacher did today. Yes, the computer and IWB let her down again!! At least this frustration is recognised by many authors. Hayes imparticular sums it up brilliantly  " ICT is a very good learning tool and a good source of motivation but often very stressful for the teacher to administer" I couldn't agree more, and on that note i'm off to bed to have nightmares about equations!! Goodnight