Go to navigation
It is currently Tue Dec 06, 2016 9:49 pm

All times are UTC




Post new topic Reply to topic  [ 11 posts ]  Go to page 1, 2  Next
Author Message
PostPosted: Thu May 31, 2012 9:25 am 
Offline

Joined: Thu Feb 02, 2012 2:12 pm
Posts: 166
Help with VR GL pack 2 test 5 Q 41

4 (12) 36
2 (6) 18
5 (?) 45

answer is 15 but can not see why

I can see that all the numbers in brackets and the right hand number are the result of x3 but thats about it. Any help as its stumped both me and DS


Top
 Profile  
 
PostPosted: Thu May 31, 2012 9:27 am 
Offline

Joined: Tue Oct 04, 2011 8:44 am
Posts: 1390
Location: Reading
that looks a dodgy one, missing number is 3 x left or 1/3rd of right. I thought you were supposed use both left and right to drive the missing one.


Top
 Profile  
 
PostPosted: Thu May 31, 2012 9:31 am 
Offline

Joined: Thu Feb 02, 2012 2:12 pm
Posts: 166
Reading Mum wrote:
that looks a dodgy one, missing number is 3 x left or 1/3rd of right. I thought you were supposed use both left and right to drive the missing one.


Me too and Im sure you do but wondered if this was an error on the paper


Top
 Profile  
 
PostPosted: Thu May 31, 2012 9:38 am 
Offline

Joined: Wed Oct 12, 2011 8:34 pm
Posts: 930
4 x 6 =24 36-24= 12
2 x6 = 12 18-12= 6
5x6 = 30 45 -30 =15

- tricky one took a while to get my head around!


Top
 Profile  
 
PostPosted: Thu May 31, 2012 9:45 am 
Offline

Joined: Thu Feb 02, 2012 2:12 pm
Posts: 166
janet71 wrote:
Reading Mum wrote:
that looks a dodgy one, missing number is 3 x left or 1/3rd of right. I thought you were supposed use both left and right to drive the missing one.


Me too and Im sure you do but wondered if this was an error on the paper


cheers :D


Top
 Profile  
 
PostPosted: Thu May 31, 2012 9:49 am 
Offline

Joined: Mon Feb 22, 2010 2:50 pm
Posts: 533
I would have worked that out as:

3x4=12, 3x12=36
3x2=6, 3x6=18
3x5=15,3x15=45

So the missing number is 15


Top
 Profile  
 
PostPosted: Thu May 31, 2012 1:19 pm 
Offline

Joined: Thu May 31, 2012 1:10 pm
Posts: 20
Or...

4 x 36 = 144 144=12x12
2x18 =36 36 = 6x6
5x45=225 225=15x15

Somewhere (one of Patricia's posts I think) I read some advice that you should always start by either + - x or / the two numbers outside the brackets first and then see how you might get from there to the number in the middle....have found this a good way to help my dd. The above is tricky I thinkbut I guess children might be expected to recognise 144 and 36 as square numbers?


Top
 Profile  
 
PostPosted: Fri Jun 29, 2012 6:26 pm 
Offline

Joined: Tue Apr 10, 2012 4:48 pm
Posts: 32
Question to Patricia may be.


My DS had a different approach, he worked out his answer like this:

4X5 = 20 20+4 = 24 36-24=12
2x5= 10 10+2 = 12 18-12=6
5x5 = 25 25+5 = 30 45-30 = 15

Pls comment if he's approach is alright.

_________________
Bm


Top
 Profile  
 
PostPosted: Fri Jun 29, 2012 8:50 pm 
Offline

Joined: Sun Mar 04, 2012 3:45 pm
Posts: 117
My working out was possibly more bizarre - I multiplied the first number by 9 to get the last number, then divided by 3 to get the middle number. Slightly different way of working it out, but I have tried my version with other questions that come up here and it always seems to work (tho' possibly I am over-complicating things).


Top
 Profile  
 
PostPosted: Thu Jul 26, 2012 10:46 pm 
Offline

Joined: Tue Feb 21, 2012 5:44 pm
Posts: 26
janet71 wrote:
Help with VR GL pack 2 test 5 Q 41

4 (12) 36
2 (6) 18
5 (?) 45

answer is 15 but can not see why

I can see that all the numbers in brackets and the right hand number are the result of x3 but thats about it. Any help as its stumped both me and DS


This is how I would approach this question. Looking at the differences there are big gaps between the sets so I considered that there might be a division somewhere. I also noticed that the last numbers are divisible by 9.

4X2= 8 ; 36/9=4; 8+4=12
2X2= 4; 18/9=2; 4+2= 6
5X2=10; 45/9=5; 10+5 =15

Hope this helps.

StacatoMum


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 11 posts ]  Go to page 1, 2  Next

All times are UTC


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
CALL 020 8204 5060
   
Privacy Policy | Refund Policy | Disclaimer | Copyright © 2004 – 2016