Help needed on this sequence question......

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Tink2010
Posts: 6
Joined: Mon Mar 03, 2014 10:10 pm

Help needed on this sequence question......

Post by Tink2010 »

Please can anyone help with this vr question?

Give the next number in the following sequence..

1 , 8 , 27 , 64 , ?

The answer given is 125 but I cannot work it out to show my daughter.
Sally-Anne
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Location: Buckinghamshire

Re: Help needed on this sequence question......

Post by Sally-Anne »

They are cubed numbers;

1 x 1 x 1 = 1
2 x 2 x 2 = 8
3 x 3 x 3 = 27
4 x 4 x 4 = 64
5 x 5 x 5 =125
ToadMum
Posts: 11946
Joined: Wed Jan 18, 2012 12:41 pm
Location: Essex

Re: Help needed on this sequence question......

Post by ToadMum »

[quote="Tink2010"]Please can anyone help with this vr question?

Give the next number in the following sequence..

1 , 8 , 27 , 64 , ?

The answer given is 125 but I cannot work it out to show my daughter.[/quote]

By my reckoning, the next number should be 117:

The difference between 1 and 8 is 7 (4th prime number)
- between 8 and 27 is 19 (8th prime number)
- between 27 and 64 is 37 (12th prime number).

The 16th prime number is 53, I think?
Outside of a dog, a book is a man's best friend. Inside of a dog it's too dark to read.Groucho Marx
Tink2010
Posts: 6
Joined: Mon Mar 03, 2014 10:10 pm

Re: Help needed on this sequence question......

Post by Tink2010 »

Ah thank you so much, she has learnt lots of difference techniques on these sequences but not cubed numbers.

Really appreciate your help :D
ToadMum
Posts: 11946
Joined: Wed Jan 18, 2012 12:41 pm
Location: Essex

Re: Help needed on this sequence question......

Post by ToadMum »

Sally-Anne wrote:They are cubed numbers;

1 x 1 x 1 = 1
2 x 2 x 2 = 8
3 x 3 x 3 = 27
4 x 4 x 4 = 64
5 x 5 x 5 =125
Ahh... :lol:
Outside of a dog, a book is a man's best friend. Inside of a dog it's too dark to read.Groucho Marx
PurpleDuck
Posts: 1586
Joined: Sat Jul 24, 2010 10:45 pm

Re: Help needed on this sequence question......

Post by PurpleDuck »

Does it ever feel to you as if it were us - parents - doing the 11+? :lol:
It felt like I hit rock bottom; suddenly, there was knocking from beneath... (anon.)
booellesmum
Posts: 611
Joined: Mon Jul 27, 2015 7:44 am

Re: Help needed on this sequence question......

Post by booellesmum »

Sometimes I look at these questions and it takes me a good while to work them out. Our poor kids have to do them in seconds under pressure. Glad those days are well behind me!
PurpleDuck
Posts: 1586
Joined: Sat Jul 24, 2010 10:45 pm

Re: Help needed on this sequence question......

Post by PurpleDuck »

Same here! :D
It felt like I hit rock bottom; suddenly, there was knocking from beneath... (anon.)
PapersOwl
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Joined: Fri Feb 12, 2016 10:41 am
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Re: Help needed on this sequence question......

Post by PapersOwl »

By my reckoning, the next number should be 117:

The difference between 1 and 8 is 7 (4th prime number)
- between 8 and 27 is 19 (8th prime number)
- between 27 and 64 is 37 (12th prime number).

The 16th prime number is 53, I think?
:shock: I think it will be to hard for little girl to understand^ but the theory is really interesting.
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