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

**. I hooked the letter**

*a***throughout my A levels, university and my career prior to teaching.**

*a*During my NQT year this hooked

*started causing me problems. My handwriting on the board is messy, and my students were often confused when I wrote the letter*

**a***a*in algebra. They couldn't tell if it was a letter or a number. It looked like an ugly 2. Over the course of my NQT year I made a conscious effort to stop hooking the letter

**, and as a result my students no longer asked me to interpret my handwriting. Well, until last week...**

*a***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:

'What symbol? The Z?'

'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:

Most tweeters confirmed that they cross their Zs to avoid confusion with 2s, in the same way crossing 7s avoids confusion with 1s.

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.

**Does handwriting matter?**

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.

Here's the same question answered by another of my Year 13s. This boy's brackets drive me crazy. Since September I've been complaining that his brackets are too much like modulus signs. He is clearly trying to fix this because the slight curve on the right bracket is an improvement on what I've seen previously.

Later in the paper his brackets become even straighter.

I will continue to berate him for this in the hope that he will shake the habit.

**Good practice**

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!).

Christian Perfect picked up on this international x discrepancy a few years ago - his article Let's talk about X is worth a read.

I have a student who does 'joined up' xs (ie he doesn't take his pen off the paper) - see picture below. They look like ns. Making x look like n is pretty unusual. Do your students have any unusual handwriting habits?

**Further Reading**

- Old Pappus' Book of Mathematical Calligraphy
- A Guide to Writing Mathematics
- Ten Simple Rules for Mathematical Writing (via Colleen Young's post Mathematical Handwriting)

I used to supervise a Greek student at university - I had to ask her to make her 'pi's clearer, as in her handwriting style, they looked like 'n's :-)

ReplyDeleteI cross my zs and my 7s.

ReplyDeleteThis is in part because one of my lecturers at university was German, thought my uncrossed 7s were 1s, and marked them wrong.

I always cross z and 7. It has caused similar discussions to yours! I have a student who hooks her as and they look exactly like 2s, I've told her she needs to not do it in her exams.

ReplyDeleteI also mix z to 7 most of the times.

ReplyDelete