How would you approach this maths question?
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How would you approach this maths question?
It's from one of the bond books.
How many times can I take 39 from 624.
Normally, I would suggest these be done as straightforward division-but this is quite hard! I did it quickly by chunking
39 x 10=390 (624-390= 234)
39 x 5= 195 (234-195=39)
39 x 1= 39
so 16 x 39 = 390
Would you tend towards getting them to do more traditional division in these questions?
How many times can I take 39 from 624.
Normally, I would suggest these be done as straightforward division-but this is quite hard! I did it quickly by chunking
39 x 10=390 (624-390= 234)
39 x 5= 195 (234-195=39)
39 x 1= 39
so 16 x 39 = 390
Would you tend towards getting them to do more traditional division in these questions?
Re: How would you approach this maths question?
I would go with which ever method they feel happiest with, if that is chunking then fine as long as the answer is right!
Re: How would you approach this maths question?
I'd get them to estimate first ....
Re: How would you approach this maths question?
If you knew it didn't have a remainder then it's really quick as you see the answer has to end with a 6, and 26 is too big, and 16 is too small, but otherwise whatever is the fastest method for that child? If they were good at pretty accurate chunking, and you had loads of preparation time, I guess I personally would move towards more formal methods if that was feasible for that particular child and would lead to greater speed and accuracy.
Re: How would you approach this maths question?
oops meantto say 6 is too small
Re: How would you approach this maths question?
Sorry to be really thick Mystery, but why does it have to end with a 6?
My DD had a Q like this, and started chunking, but it took ages and she didn't get the right answer in the end.
Is there a simple explanation for really struggling mothers?
My DD had a Q like this, and started chunking, but it took ages and she didn't get the right answer in the end.
Is there a simple explanation for really struggling mothers?
Re: How would you approach this maths question?
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Last edited by Belinda on Thu Nov 01, 2012 2:18 pm, edited 1 time in total.
Re: How would you approach this maths question?
I'll be bold and show my ignorance here. Mystery, how do you know the answer must end in a six?
I'd just go down the straight long multiplication route. They haven't touched on it at school yet. If they don't soon I'll have to teach them and they don't understand my old maths approach.
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I'd just go down the straight long multiplication route. They haven't touched on it at school yet. If they don't soon I'll have to teach them and they don't understand my old maths approach.
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Re: How would you approach this maths question?
chunking leads on to long multiplication really well and helps them understand what is happening with long division.menagerie wrote:I'll be bold and show my ignorance here. Mystery, how do you know the answer must end in a six?
I'd just go down the straight long multiplication route. They haven't touched on it at school yet. If they don't soon I'll have to teach them and they don't understand my old maths approach.
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which ever method you use, the estimation is a really good first step
Re: How would you approach this maths question?
Have just asked DS1 to do this sum..a nice little post dinner teaser for him... and he came to 16 straight away and said he multiplied 39 by 10 to get 390 and then just added on each 39 up to 624.Not sure if that's the easiest way ?