# The Alfred Hitchcock Lesson

## How a maths lesson was given some mystery and suspense

Sometimes I hear about schools that have a day dedicated to a particular theme. It might be 'Health Awareness Day' or a day on 'Careers in STEM'.  These are worthy and important causes, but I suspect they don't set many pulses racing.

But let me tell you about the day my nephew's secondary school did something different.  The school decided to have a Movie Day.

Every teacher was encouraged to pick one of their favourite films, and then build a whole lesson around it.

My nephew's science teacher picked Star Wars, and investigated the feasibility of some of the technology. His history teacher chose The Life of Brian to start a discussion on what the Romans did for us.

And then there was the maths teacher, Mr Gleeson.  Mr Gleeson decided to theme his lesson around his favourite Alfred Hitchcock film, North by Northwest.

At the start of the lesson, Mr Gleeson explained a little bit about Hitchcock, and how he was the master of suspense.  He showed the class the original poster for North by Northwest, starring Cary Grant.

"Right," he said, "I am about to play you the opening titles of the film.  And I'm going to follow it with a question.  I want you to see if you can guess which question I am going to ask."

The lights dimmed, the MGM lion roared. and the edgy staccato theme tune began, as thin black lines seeped in from the top and the right hand side of the green screen.

As the name of the film appeared at the end of the credits, Mr Gleeson froze the screen.  "Any idea what my question is?", he asked.

"Is it 'what angle are those lines at?'", asked one boy.

"No." (But Mr Gleeson noted down the question).

"Is it 'which maths symbol appeared in the titles'?'"

"No."

"Is it 'what does north by north west mean'?'"

"No"

When the class ran out of questions, Mr Gleeson revealed his question one word at a time, pausing to see who could guess it.

WHICH.....OF.....THESE.....LINES....ARE.....

"Parallel !" shouted a girl at the back.

"Yes, well done, you win!  And I have another question that none of you suggested: These lines are going to turn into something - where would you find these lines in real life?  I'm going to answer that question at the end of the lesson, but before that, let's answer the other questions.

For the next 50 minutes, the class were reminded of what parallel lines are (and discovered that none of the lines in the opening titles of North by Northwest are parallel);  they learned what 'North by North West' means on the compass, and what angle it is from north;  and they watched the famous crop-dusting scene and plotted a map of Cary Grant's movements in and out of the corn field.

But one mystery was left until the end of the lesson.  Mr Gleeson asked them to guess what those vertical and slanting lines were going to turn into 'in real life'.  There were lots of guesses but none of them were right.

At this point, Mr Gleeson pressed play to continue the titles.  Slowly the lines transformed into the windows on the side of a city office block - the building where Cary Grant works.

For one hour, that maths lesson had lived up to Hitchcock's reputation of mystery and suspense.

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I have told this story to several maths teachers and parents.  They are always intrigued.  "That sounds exciting, what a great idea, I wish my maths lessons had been like that, which school was it?"

And then I confess.

The whole story is fiction.  It never happened.  There is no Mr Gleeson, and my nephew has never had a maths lesson like that.  But it does raise the question: Why Not?.  It COULD happen, couldn't it?  If you are a maths teacher, maybe you are the one who will bring this little fantasy to life.