Getting to grips with maths

The last time I did any maths was a GCSE in 1991- and I mean real maths, not splitting a bill, checking my change or counting children on school trips.  But even these things are done using my own idiosyncratic method and I don’t show my working.  So I probably wouldn’t get any marks for them in an exam, even if I arrived at the right answer and realised that 37 – 1  meant that I had left a child in the service station 20 miles back.

So I thought I’d better put in some practice before I have to start teaching maths in Cambodia next month, and I got out the list of topics.

Topic number one: complementary numbers.  So I googled it and learnt that ‘a complementary number, in number theory, is the number obtained by subtracting a number from its base. For example, the complement of 7 in numbers to base 10 is 3.’

So I googled base number.  Apparently it is ‘a number which is going to be raised to a power.’

So I googled power.  This tells you how many times to use a number in a multiplication.

I think I get this last one, it’s like squared or cubed, but the other two are definitely still fuzzy … I can’t help thinking of numbers raised to a power as being despotic – probably plotting a violent coup and fighting me every step of the way as I struggle to subtract them from their bases.  If it comes to a showdown between me and the numbers, I’ll put my money on the numbers winning – although I will be able to use my idiosycratic methods to check my winnings and make sure I haven’t been short-changed.

I have decided to abandon complementary numbers and start with number patterns instead, as they sound far less threatening.  I will post a progress report next week.

Image result for image of numbers



Cambodian Research

Last summer I decided to take a course to learn to teach English as a foreign language.  One year on, despite passing with flying colours, I still haven’t found an opportunity to use my new-found skill.  So, with ‘use it or lose it’ firmly in my mind, I have arranged to spend seven weeks in Cambodia this summer volunteering in a children’s project in Siem Reap.

This week I received my teaching instructions, and my class is ‘Tigers and Rhinos’.  I’m hoping that this is just the name of the class, and not a zoological classification of the class members.  I will be teaching them English (good – I’m prepared for that), Geography (erm … not exactly my forte) and maths (gulp … definitely not my forte).

But with my customary enthusiasm I have thrown myself into the necessary research.  The geography module is all about Siem Reap province, which is slightly worrying as they live there and I don’t, so they should probably be teaching me about it.  But thanks to Google I am now au fait with the reverse water flow of the Tonle Sap River and the problems facing the giant catfish who live there.


The maths is a different matter.  One of the topics is doubling, which seems fairly straightforward – we can work in multiples of giant catfish – but there is also complementary numbers and non-numerical patterns on the scheme of work … more googling required, I think.