Primary school maths techniques

PaulStat

PaulStat

PaulStat

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Just been doing some maths homework with my son who's in year 2. So early questions were easy enough and I can see the technique they're using for example

addition (add the tens then the ones, tens are the |'s and ones are the .'s)
Code: 
23 + 11

||... + |. = 34

or a subtraction (remove the tens and ones and then see what's left over)
Code: 
23 - 11

|.. = 12

Now for the slightly more complicated examples

eg. (addition I got him to write down the ones first and then add an additional ten unit to one side, not sure of the official technique here but it made sense to me and him importantly)

Code: 
23 + 18

||... + |........ =  1

becomes

|||... + |........ = 41

But for more complicated subtractions I'm not sure how they use this tens and ones technique?

eg.

Code: 
55 - 37

Obviously I can ask his teacher next week, but does anyone know what methods they teach them here?
 
I don't get your 23 + 18 logic.

Surely you you follow the same logic as before but replace 10 dots with a line afterwards.

Once you learn that ten dots and a line are interchangeable, you will realise you can break a line back into 10 dots and hence do complicated substraction.

This does seem like a good way to learn a decimal number system.
 
Prolly best google for official method or ask teacher, many top bods(apparently) working out these techniques, don't want to be learnig bad habbits.
 
kindai said:
This seems weird and convoluted.
Click to expand...

Not only me that thought this then, It seems to me that that somebody has gone out of there way to find the most complicated way to teach simple maths. What ever happened to numbers on top of each other, counting down and carrying for addition e.g.

Code: 
  23
+11
=34

For subtractions its the same e.g.

Code: 
55
37

5-7 = -2
50-30 = 20
20 - 2 = 18.

I guess that I am just a little lost in what it is you are asking?
 
Vince said:
Not only me that thought this then, It seems to me that that somebody has gone out of there way to find the most complicated way to teach simple maths. What ever happened to numbers on top of each other, counting down and carrying for addition e.g.

Code: 
  23
+11
=34

For subtractions its the same e.g.

Code: 
55
37

5-7 = -2
50-30 = 20
20 - 2 = 18.

I guess that I am just a little lost in what it is you are asking?
Click to expand...

Yea this is how I was taught also.

Though dont ask me how to do long division, no freaking idea how I was taught that but can multiply and divide in my head easily :D
 
muon said:
I don't get your 23 + 18 logic.

Surely you you follow the same logic as before but replace 10 dots with a line afterwards.

Once you learn that ten dots and a line are interchangeable, you will realise you can break a line back into 10 dots and hence do complicated substraction.

This does seem like a good way to learn a decimal number system.
Click to expand...

Ah yeah duh that does make sense, so using this method it work make more sense like

Code: 
23 + 18

||... + |........

becomes

|| + ||. = 41

still not sure how they would represent that subtraction though

Vince said:
Not only me that thought this then, It seems to me that that somebody has gone out of there way to find the most complicated way to teach simple maths. What ever happened to numbers on top of each other, counting down and carrying for addition e.g.



Code: 
  23
+11
=34

For subtractions its the same e.g.

Code: 
55
37

5-7 = -2
50-30 = 20
20 - 2 = 18.

I guess that I am just a little lost in what it is you are asking?
Click to expand...

Yeah that's the way I learnt it too but I don't want to confuse him by teaching him my technique
 
Last edited:
PaulStat said:
Yeah that's the way I learnt it too but I don't want to confuse him by teaching him my technique
Click to expand...

It just seems madness they way they teach things these days. I get that some of these methods are teaching them more than just the math but I can see how a 8 year old might get confused with the (substitution?) method in the op.
 
Jumping straight into adding digits together doesn't teach you fundumentally about numbers. What do you think carrying the the 1, borrowing a 10 means to a 7 year old?

Whilst this is literally teaching you first principles making you understand that the number 8 is just an abitrary name given to a quantity. 10 is an arbitrary denomination

When people learn maths from first principles they are far better at maths and crucially better at answering something they haven't come across before.

You have all been taught how to do 356 - 98. But someone who understands the fundumentals of what numbers are, will be able to work that out without being told how to do it.

This is a fantastic way to teach the decimal system. In fact a child who isn't tied down by the decimal system would be able to do maths with other bases more easily.
 
So I decided to get the notebook out and have jotted down what i think they are trying to teach your little one:



I had a little google and it appears it's called verbal reasoning and is part of 11 plus prep.
 
Vince said:
So I decided to get the notebook out and have jotted down what i think they are trying to teach your little one:



I had a little google and it appears it's called verbal reasoning and is part of 11 plus prep.
Click to expand...

This would be non-verbal reasoning.
 
Vince said:
Not only me that thought this then, It seems to me that that somebody has gone out of there way to find the most complicated way to teach simple maths. What ever happened to numbers on top of each other, counting down and carrying for addition e.g.

Code: 
  23
+11
=34

For subtractions its the same e.g.

Code: 
55
37

5-7 = -2
50-30 = 20
20 - 2 = 18.

I guess that I am just a little lost in what it is you are asking?
Click to expand...

Just think about what you are doing in that 55-37 calculation. Is that actually teaching you what numbers are, or just giving you a method of subtracting numbers?

If you mentally work it out, are you actually doing that?
 
muon said:
Just think about what you are doing in that 55-37 calculation. Is that actually teaching you what numbers are, or just giving you a method of subtracting numbers?

If you mentally work it out, are you actually doing that?
Click to expand...

I take your point and I imagine trying to explain to a child why it's not 20 - -2 might be a tad tricky ;)
 
kindai said:
This seems weird and convoluted.
Click to expand...

this really, I'm not really seeing the argument that this is really needed in order to understand 'what numbers are'

perhaps it is aimed to ensure even the slowest kids are able to grasp some basic numeracy at a young age, there are however plenty of kids quite capable of getting a basic understanding without having to resort to convoluted methods like this... it seems a bit like the weird stuff introduced in US classrooms in recent years
 
Totally unintuitive way of teaching.
Same at my children's school, teachers probably get bigger bonus for using it.

And they wonder why kids leave school unable to do the basics.
 
To be fair I thought kids were still taught the basis of what numbers are on an Abacus, I certainly was as a kid. Is this not a thing anymore?

 
Vince said:
To be fair I thought kids were still taught the basis of what numbers are on an Abacus, I certainly was as a kid. Is this not a thing anymore?

Click to expand...

That would probably achieve similar results and a lot faster... the OP says year 2 - I assume that it the last year of infant school? You could start with an abacus earlier than that tbh... In fact this 'new technique' is basically re-inventing a crap version of the same thing by making it much more tedious and boring as they write out a bunch of 1s
 
dowie said:
That would probably achieve similar results and a lot faster... the OP says year 2 - I assume that it the last year of infant school? You could start with an abacus earlier than that tbh... In fact this 'new technique' is basically re-inventing a crap version of the same thing by making it much more tedious and boring as they write out a bunch of 1s
Click to expand...

They aren't taught this so they can carry on writing out lots of dots. But instead to be able to do this in their head.

Unless of course you were using your abacus in year 6 to add or subtract 2 numbers.
 
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