Maths

11 Plus Maths – Preparation and Information

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polly0494
Posts: 91
Joined: Fri Aug 22, 2008 12:08 pm

Maths

Post by polly0494 »

I am struggling to guide my daughter with this question:

If 12 is subtracted from 1/10 of a certain number and the answer is 13 what is the number?

Can anybody help?

Thanks

Polly
stevew61
Posts: 1786
Joined: Fri Nov 17, 2006 9:54 pm
Location: caversham

Re: Maths

Post by stevew61 »

polly0494 wrote:I am struggling to guide my daughter with this question:

If 12 is subtracted from 1/10 of a certain number and the answer is 13 what is the number?

Can anybody help?

Thanks

Polly
Hi,

Try drawing a function machine or a sum with an empty box.

The trick is to work from back to front, in this case.

So, 13 equals (a number divided by ten) minus 12.

So 13=25-12, so 13=250/10-12. So 250?

Did I get the right answer? :shock:

Where is G55 when you need some maths help. :cry:

steve
emmajane1
Posts: 91
Joined: Thu Jan 15, 2009 4:22 pm

Post by emmajane1 »

You need to reverse the proceedure - 12 +13 = 25

25 is 1/10 of the number thus the number must be 250.

hope this helps

Emma
polly0494
Posts: 91
Joined: Fri Aug 22, 2008 12:08 pm

Post by polly0494 »

Thanks for the quick replies!

It's been a bad day at the office and I could not explain it! :oops:
essex-mum18
Posts: 218
Joined: Sun Nov 25, 2007 12:09 am

Re: Maths

Post by essex-mum18 »

polly0494 wrote:I am struggling to guide my daughter with this question:

If 12 is subtracted from 1/10 of a certain number and the answer is 13 what is the number?

Can anybody help?

Thanks

Polly
There is another approach

We do not know what the number is, so make it as X

(1/10 of X) -12 = 13

(1/10 of X) = 25

Therefore X = 250

Hope this helps
polly0494
Posts: 91
Joined: Fri Aug 22, 2008 12:08 pm

Post by polly0494 »

Thanks everybody for your replies.

Ny daughter and I have worked through it using the suggested methodologies and seems to get it! I am going to write a few more like this for her later and see if she can work them out!

Thanks again,

Polly
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