A bit late in getting to see this film, I admit, which is perhaps a curse rather than a blessing as I seem to have forgotten any negative reviews and went in with high hopes. And for the record, before we begin, I haven't read the book. So:
How's the movie?
Well, let's be fair and say that it all looks terribly, terribly nice up there on the screen - or should I say tahbly, tahbly ness, in keeping with the movie accents? There's some impressive cinematography, but by heck they want you to know about it, so it's hard to lose yourself and get really caught up in the story. I believe the book unwinds in a tricky manner that lets on from the outset that one of the central characters is telling the story, so it would be nice to think that what was going on here was that the film-makers were playing with the idea of someone making a film about the story... but that would be crediting them with more than they deserve.
The film hinges on a misunderstanding (wilful or otherwise), from which follows much woe - gorgeously cinematic woe, never fear - but to be honest it's hard to care over much, or not to feel at the end of the two hours that you really didn't need to bother. Whereas a misunderstanding offers much in the way of comic potential, there's not many laughs to be had here - although there were titters from the audience at one point in the film which I think was meant to be very erotic.
So anyway: go see it if you want. It looks nice; the actors do their bit; war is terrible; atonement is... well, what exactly I don't know and nor do they; and that's your lot. Can they have a Bafta now please?
How's the maths
Oh, dahling, I'm afraid everyone's far too frightfully posh or clever to talk about mathematics - don't be such a bore. Pass me another ciggie, won't you?
Can I teach with it?
Well, in the movie world time is seldom linear and much more a big ball of timey-wimey stuff, and seldom more so than here, as the scenes jump forward and back over (eventually) about 70 years. A chance then, surely, to apply negative numbers in context: let the initial scene have value t=0 (years), in which case (ooh, here comes a flashback) this must be t=-2, and then boom! it's Dunkirk so t=3, but wait now (blimey! it's Vanessa Redgrave) t=70... and so on.
However, be warned: the central conceit mentioned earlier does include a letter from one character to another, containing the use of a certain four-letter word (and not the one starting with f, either) ... and I think you can safely wave goodbye to your teaching career if you let that crop up during the DVD. All the same, I daresay the History department will happily borrow it from you in order to show that war is A Bad Thing.