In typical younger sister style, I attempted to copy his cool handwriting. I wasn't as dedicated as he was, but I did begin to put a hook on the top of the letter a. I hooked the letter a throughout my A levels, university and my career prior to teaching.
The crossed Z
I was going through a Normal Distribution example on the board when a Year 13 raised his hand.
'Miss, what does that symbol represent?'
I was flummoxed for a second. This class were studying S2 - they'd learnt the Standard Normal Distribution in Year 12, so the notation should be familiar. I looked at what I'd written on the board:
'Oh, is that a Z?'
'Yes, it's a Z.'
'Why does it have a line through it?'
'That's what Z looks like. Or perhaps it's just how I write it. I suppose it's so it doesn't get confused with a 2. Does anyone else here cross their Zs?'
All 11 students shake their heads.
'Oh. I thought everyone did. I'm not sure when I started doing it. But I always cross my Zs.'
I wrote the word lazy on the board to demonstrate my crossed z. They looked at me like I was crazy. Self doubt crept in.
I did a Twitter poll and thankfully it confirmed that the way I write the letter Z is totally normal (pardon the pun) amongst maths folk:
I had a fascinating tweet from air traffic controller @jlaa who has to make sure he doesn't cross his 7s because a crossed 7 has a very specific meaning. The picture below shows flight details written on strips - both show that the aircraft has been told to descend from 7000ft to 5000ft. In the bottom picture it is safe to issue 7000ft to another flight but in the top picture it isn't. He has to be very careful not to automatically cross his 7s.
I teach a Year 13 Further Maths class and most of them are going to study maths or engineering at university. I talked to them about mathematical handwriting for the first time last week. They were interested, and it led to discussions about notation such as the use of dots for multiplication and commas for decimal points. I felt like it was a discussion worth having.
When letters are unclear in words we can normally interpret the meaning by considering the context or looking at the other letters. But when letters and numbers are unclear in mathematics we might not have any clues. This can be a problem for exam markers, particularly if they are marking individual questions so can't refer to the rest of the paper for clarity. My colleague told me she has a Year 10 student who writes the numerals 9 and 4 in exactly the same way. He may well end up losing marks in his GCSE because of this.
Here's some pictures from my Year 13 students' mock C3 exams. The first student has trouble with his ones. He hooks the top and draws a line at the bottom so they sometimes look like twos. In this picture it's clear, but only because there are twos there for comparison.
I will continue to berate him for this in the hope that he will shake the habit.
I think that guidance on mathematical handwriting should be delivered in Year 7. The importance of clear handwriting - and tips such as the crossing of the 7 and the Z - should be made explicit. This post Tips for mathematical handwriting is a good starting point (though teachers from outside the US won't be happy with the letter x here!).
Let's talk about X is worth a read.
- Old Pappus' Book of Mathematical Calligraphy
- A Guide to Writing Mathematics
- Ten Simple Rules for Mathematical Writing (via Colleen Young's post Mathematical Handwriting)