I'm sure by now you have heard me mention that I teach a lot of resitters where they may be sitting the GCSE for the second, third, fourth or however many time. I've also talked about those quick wins in those early weeks to earn their trust help them gaining confidence and to deepen their mathematical understanding. One of the easiest ways I've found to do this is through teaching students how to multiply correctly. As part of my PGCE training I was asked to teach a year 7 group a series of lessons covering every possible type of multiplication that I could find available. It led me to Egyptian, Chinese and many other types of multiplication. I became familiar with a wide variety of multiplication techniques that I had to fully understand before I could explain them.
My own knowledge needed to be sound and secure before I explained them to the attentive year 7’s hanging off my every word. There are some elements of teaching year 7 that I miss greatly! Chinese multiplication became my new favourite thing. I know only multiply this way, much to my builder and husband’s annoyance when planning our new extension! I'm sure you've seen it before the lattice method the Geloise method or simply Chinese multiplication.
What I want to discuss here is the importance of being able to multiply correctly including decimals. Like I always say if you have a way that works for you than that's the way you do it what I'm offering you is a way if you can't do it consistently correctly. Many of my learner's come to me unable to multiply correctly they have been taught the grid method in primary school and they don't know what to do when they're lining them up for the final addition.
Take a look at this work this is typical of my students work. The grid is correct but the place value when adding is appalling. Yes, I am aware I will need to re teach place value but will these mistakes arise again after we have done that unit? What would happen if we looked at Chinese multiplication instead?
Look at the lattice method above. Here we have the correct answer in a much simpler way. Place value is correct. This makes me happy. I like the Chinese/lattice method because it promotes place value. I like the fact that it only uses the times tables up to 9 x 9 and although we teach up to 15 x 15 often up to 9x9 is secure and above that can be a bit sketchy in my experience.
But the real reason I like the lattice method is because of the power it has to unlock learning for many resitters. I say to all my trainee teachers and staff that I mentor. Teach someone to multiply correctly and they will be set for life. It is true, multiplication is one of those skills people have had negative experiences with and switch off. To be able to show someone how to multiply correctly can sometimes be transforming. A colleague (not a student or a teacher) was trying to multiply the number of tickets and the cost of tickets to budget for the cost of a conference for her team. She was struggling. I showed her lattice multiplication ( I drew the grid) she loved it. She was so overwhelmed she began to tear up. Maths, multiplying decimals in particular, had always been a struggle for her but she felt that it wasn’t anymore. That is the power of being able to multiply correctly. Lattice may not be the best way for everyone but I think it is worth spending the time to teach learners how to multiply correctly, including with decimals, to provide the skills that are needed for life, not just GCSE.
