WIBU to just teach DS how to do 'normal' division and multiplication?

[morninglive]

He is 7 and homeschooling via zoom. Teacher did some work where the kids had to use a model bar to multiply lengths of metres cm and mm, to make the larger length. as in - the house has storeys 4m 30cm and has 5 storeys. how tall is the house? As if multiplying and division in lengths isn't hard enough!

Instead of a straightforward multiplication in columns she did 4x5=20. 3x5-15. add them together and then some other shit. I just didnt understand it. Then a similar thing with division. Just gave the lengths of rope and said x 5 will give us the length of the uncut rope. Another example ...we have 350, halve it to get the two lengths of ribbon. But no explanation of how to halve that number. I think DS is very average so he couldn't even get started.

AIBU to say just teach in a secondary level way, but keep the numbers very simple. I am not talking long division here, or fractions of numbers (we also had those along with the metric shit) Yesterday was horrendous

I would try to understand how they are teaching it and do it the same way. It can't be that hard if they are teaching it to 7 year olds! It's likely to confuse and frustrate him to learn a different method, because he will be expected to be able to do it their way as well. It's not just about getting the right answer.

He will pick up on your attitude so make sure you don't let him see that you think the method the teacher is using is too difficult or pointless. Otherwise he will probably lose interest altogether.

There are many different methods of multiplying and dividing. It sounds like this method is not how you were taught but this doesn't make it 'shit'.

Why not listen again or look it up and give it a go?

The way they teach maths now is different but once you understand it it's logical - more so than the old way. It's a system that helps them understand the concepts better and by showing more than one way each child finds a way they understand.

That's a much more intuitive way to do multiplication than the "follow this rule regardless of whether you understand why or not" method that you were potentially thinking of teaching him. I assume the teacher is teaching age relevant curriculum. Maths is taught in ever increasing circles, so if he didn't get it today, maybe he will next time it is revisited.

They're doing it like that so he understands why it works not simply getting an answer.
He'll have to do it that way in school so try to get your head round it .

It's really important he understand what she's doing as it's the basis of the 'normal', formal method of column multiplication. We teach children all these steps along the way so that when they see the formal method they comprehend it, can use it properly and unpick it if things go wrong.

Often formal written methods that parents want to teach don't teach understanding. So they just follow a method but don't know why. Often by yr6 pupils will use the quick written method but by then they should have a good understanding of what's going on with the numbers. Imagine you had to do a large ish multiplication in your head. If you only knew how to do it one way using pen and paper, that would be very limiting. Also if you made a mistake you wouldn't be able to spot it because you don't understand the mathematical concept behind the method. So in conclusion I'd try to go with the teacher way. You could ask them to explain further if you don't get it.

They teach it differently now. Show support to teacher. Plus he'll need to know that way, because he'll be tested on it, in exams.

But no harm in showing other methods. So long as you explain very clearly that this is a different way of doing it and that it is an added bonus to him.

It sounds like your son’s teacher is just teaching them mental arithmetic. multiplying 4m30cm by 5 can be done in a few ways but hers sounds like one of the easiest. I would have thought it was easier for a 7 year old to deal with the 4m first, then the 30cm (0.3m), then add them together, rather than converting it into 4.3m and trying to multiply that by 5 all at once? It’s exactly the same thing as doing it in columns just without writing it down.

Can anyone then explain how to do 350x5 using the correct method?

And 250 divided by 6 as an example of division?

The teacher goes quite fast and the kids are all butting in so I can't get what she means, as well as trying to help DS understand it as well.

Teacher is probably sick of parents emailing her.
Thank god schools return in a week or so!!!

@Babyiskickingmyribs She is keen for the kids to convert everything into the smallest length, so 430 cm. Then convert it back, although for the 4m30cm one she did it in the given lengths. Only one more day til the weekend.

You should really try and understand why the teacher is doing it that way - or else when he goes back to school he will get very confused. We did this with my daughter, it was a disaster.

Halving 350 can be approached in a similar way. Split it into 300 and 50. Half of 300 is 150 and half of 50 is 25. 150+25 is 175.

These methods need kids to have some basic facts memorized. Can your son count in 10s? What about 15s? Or 25s? 15s work well with clocks. 15minutes is a quarter chunk of a clockface. Two quarters of a clockface is 30minutes. So half of 30 is 15, which means half of 300 is 150. 25s are good with money. Four lots of 25p make 1pound. 2 lots of 25p make 50p.

Bars of chocolate with 10squares work well for learning decimals. And then you get to eat them afterwards :)

What I’m saying is, you can improve your son’s understanding of maths by linking numbers into these everyday things. It helps to make numbers and fractions less abstract.

Is it weird that I multiplied like she did? And I'm 34. Hahaha. I always break it up and then add it together. 250 divided by 6, however, isn't a whole number so I've no idea! I do feel you, my son is only 5 and phonics alone makes my head hurt. I try to teach it to him how they do and hope for the best. Not long!

You talk about using bars. That sounds like bar modelling which is a method adopted from Singapore that visually represents problems and is used for understanding worded problems or logic puzzles. This sheet on tes explains it. www.tes.com/teaching-resource/solving-word-problems-using-bar-model-multiplication-and-division-11848568

The end goal will be "normal" multiplication and division but you cant go straight in at the end goal with young children. They need to take lots of small steps before they get there. They also need to understand what they are doing. 4.3 x 5 will mean nothing to a 7 year old. Knowing that something is 4m 30cm long will.

250 divided by 6. I would split it into 240 and 10 and we’ll ignore the 10 till the end. 240 is a nice number for dividing by 6 because 24=6x4. So 240x6 is 40. 10 divided by 6 is less nice. It doesn’t fit. You get 1 full six then 4 left over. 4 is only 2/3 of 6. So either the answer is 41 remainder 4 or 41.666 with the decimal going on forever. I’m not a teacher by the way, this is just how I do mental arithmetic but it does seem to fit in with what your son’s being taught. Does your son know his times tables? Not just in order like a song or chant, but out of order too? The 250/6 example will be difficult if he doesn’t know that 4x6=24

Does your son have lego? Lego is great for maths because the bricks have dots on them and you can count bricks or dots and it’s easy to see if things are equivalent.

@Babyiskickingmyribs

250 divided by 6. I would split it into 240 and 10 and we’ll ignore the 10 till the end. 240 is a nice number for dividing by 6 because 24=6x4. So 240x6 is 40. 10 divided by 6 is less nice. It doesn’t fit. You get 1 full six then 4 left over. 4 is only 2/3 of 6. So either the answer is 41 remainder 4 or 41.666 with the decimal going on forever. I’m not a teacher by the way, this is just how I do mental arithmetic but it does seem to fit in with what your son’s being taught. Does your son know his times tables? Not just in order like a song or chant, but out of order too? The 250/6 example will be difficult if he doesn’t know that 4x6=24

That is amazing! Honestly couldn't be more impressed.

250/6 illustrated with duplo :

Photo 1. A helpful block with 32 dots, arranged in 8 rows of 4. (8x4=32)
Photo 2. Meg and mog is covering up some of the duplo block now we have 6 rows of 4. There are 24 dots (6x4=24).
Photo three. Meg and mog moves to show one extra dot. (6x4)+1=25.
Now pretend each dot has 10 miniscule lego mites living on it (or 10 invisible bunny rabbits or tiny dragons or whatever will make your son laugh). So 250 lego mites in photo 3. Each of the 6 full rows has 4 dots or 40 tiny dragons in it. And there is one dot containing 10 tiny dragons left over in the partial row. We could split up the 10 extra dragons and put one in each of the 6 rows and there would be 4 left over. Then either we have 6x40dragons remainder 4 or we have to cut the 4 remaining dragons up into thirds to finish splitting evenly.

Just beacuse you don't understand it doesn't make it wrong. It is fine to show alternate ways to multiply and divide but maths is taught the way it is today to encourage understand rather than rote learning of methods with no understanding of why. This helps children make links between numbers and gives real context. There isn't 1 correct way.

You could perhaps ask his teacher for more supprot or you could watch tutorals online (YouTube will have lots) if you know the specifc method being used.

I learnt maths in the 70s and 80s and have vivid memories of my mother going "that's a ridiculous method, I learnt to do it like this!" And then showing me a totally different method, with the end result that I hated maths and found it confusing and scary to the point that I still add up on my fingers to this day and have to draw domino dots in the air to count. One method, and stick to it!

Sorry the extra dot isn’t really in a partial row, more tacked on to the last row. But the idea still works.

I avoided just teaching my six year old the “proper” way - until I realised that’s the method she’s naturally doing in her head. So I just thought sod it, and got her doing it the HTU way like we did at school. I feel a bit bad for when she goes back to school, but expecting me to teach a method that seems so clunky, to a (bright) child who doesn’t get along with it, just seems to bloody pointless.