A great multi-level exercise. The outcome of all versions should be the same -correcting the mistakes in the postcard. But altogether there are three versions of the same postcard with instructions suited for less and more advanced Ss within the same group. Weaker Ss can get the postcard A-where the specific kinds of mistakes are colourfully highlighted; for stronger Ss the mistakes are only underlined and they should decide what kind of mistake it is, version C, the most challenging, is for the best Ss in your group - they find the mistakes for themselves and correct them. This way all Ss get engaged in the same exercise and they won't get bored! Tricky, isn’t it? ;) Good luck.
It’s difficult to motivate Ss if you have mixed-ability groups. Good luck. I think this activity should do the job. Happy teaching to all of you ;)
The key is included.