Mental Maths or Working Out solutions on paper

[GTJLondon]

DS is in Y5 and seems comfortable with Maths. He understands the concepts and is good with operations and times tables.

However, he always tries to do maths mentally. No matter what kind of problem it is, he doesn't workout on paper but calculates mentally. He also has his own methods or ways of calculations, like if he has to subtract a 3 digit number from a 4 digit number, he will not use the column method but try to round off the numbers to nearest 10000, 1000, 50 etc and calculates mentally.

This method works fine but firstly its time consuming and secondly he tries to apply it to even bigger numbers which is difficult to do mentally. So even after knowing the method correctly he get answers wrong sometimes.

I have been trying to make him understand that he needs to start working out the solutions esp for bigger numbers, tricky questions and word problems, but he is so much into mental methods that he struggles to put anything on paper.

How do I make him take up working out solutions on paper as some questions are easier understood when visually represented and tried.

Or is it fine to let him continue with mental calculations. If yes, how can he improve the accuracy of mental calculations?

Thank you

Just let him get on with it. Why do you feel the need to interfere

^ GoingForAWalk

Just let him get on with it. Why do you feel the need to interfere^

That’s a strange, slightly angry, response.

Because the OP cares about her son?

Because as we all know when it gets to exams if they can’t show their working on paper they will lose marks?

Because even if you get your answer wrong in an exam if you have shown your working you might hover up some marks by demonstrating you know the principles?

Because it’s good practice to start writing things out now because as maths gets harder I don’t expect anyone except the very very brightest can do it mentally.

Because he’s not getting it right, and if he wrote it down the chances of him picking up mistakes is greater.

On the other hand you put him off maths for life by insisting he labours through writing it down when he doesn’t want to.

I don’t know OP. I’ve just had a similar conversation with my ds’s yr 2 teacher who is cross as my ds can easily do the work mentally but won’t write out the sums, just the answer.

I’ll be reading any answers you get.

Yes he needs to write it all down! Especially if the question states "show your calculations" if he goes wrong they will still give him marks but if he just writes a wrong answer then he won't get any marks!!

Ds2 always did mental calculations and when asked how he got the answer his reply was I did it in my head. His teacher told him that whatever method he was using in his head he needed to get down on paper because they mark the working out as well as the answer. That was in primary school.

It didn't matter whether he did the column method, he just had to show how he did it. Ds writes down what he is doing but usually mentally calculates stuff and writes down the answer. Therefore there is no official working out on paper just what method he is using so it shows how he came up with the answer.

It might not matter so much in primary (but it still does) however in secondary when there are 5 mark questions he absolutely needs to show his working out so best get him into the habit now. Re accuracy of mental maths, just practise and check with a calculator.