It is currently Tue Dec 06, 2016 12:48 am

 All times are UTC

 Page 1 of 1 [ 6 posts ]
 Print view Previous topic | Next topic
Author Message
 Post subject: help with fractionsPosted: Tue Feb 24, 2009 9:30 pm

Joined: Tue Oct 28, 2008 10:05 pm
Posts: 100
Hello, please could anybody help me with this: calculate 3/8 of 980. I'm sure it's very simple but i'm no good and i'm hoping I can show your reply to dd.

this is year 6 homework and I think it may be a sats type of question as the sheet is from the LA assessment team

many thanks

b

Top

 Post subject: Posted: Tue Feb 24, 2009 9:42 pm

Joined: Mon Oct 06, 2008 1:41 pm
Posts: 686
Location: South Wilts
Calculate 3/8 of 980

Divide 980 by 8 = 122.5
Multiply by 3 = 367.5

or
Multiply 980 by 3 = 2940
Divide by 8 = 367.5

Remind her that fraction questions are division sums when concerning the denominator (bottom number), and multiplying sums when concerning the numerator(top number), or in this case a bit of both!

Top

 Post subject: Posted: Tue Feb 24, 2009 9:45 pm

Joined: Mon Feb 12, 2007 1:21 pm
Posts: 11940
1/8 of 980 means 980 divided by 8 = 122.5

so 3/8 means 3 x 122.5 = 367.5

Top

 Post subject: Posted: Tue Feb 24, 2009 9:49 pm

Joined: Tue Oct 28, 2008 10:05 pm
Posts: 100
many thanks from me & grateful dd sycamore!

Top

 Post subject: Posted: Thu Feb 26, 2009 10:38 am

Joined: Thu Jan 12, 2006 3:29 pm
Posts: 625
Hi

When you see "of" in a fraction sum, this means "times", so 3/8 of 980 means 3/8 x 980.

An alternative method for multiplication of fractions is to reduce the numbers down.

3/8 x 980

The 8 and 980 can be halved, giving

3/4 x 490

The 4 and 490 can be halved, giving

3/2 x 245

The top line in a fraction are multiplied giving,

3 x 245 = 735

and this is divided by the number in the bottom line giving,

735 divided by 2 = 367.5

Here is another example of cancelling down fractions:

8/9 x 15/32

You cancel down any top number with any bottom number

8 and 32 can be cancelled, by halving, to 4 and 16, then 2 and 8, then 1 and 4, giving

1/9 x 15/4

9 and 15 can be cancelled down, by dividing by 3, to 3 and 5, giving

1/3 x 5/4

Multiply top line, then bottom line gives the answer,

5/12

Regards

Mike

Top

 Post subject: Posted: Thu Feb 26, 2009 1:45 pm

Joined: Tue Oct 28, 2008 10:05 pm
Posts: 100
Thanks Mike & guest 55

I will show your replies to dd when she gets home!

b

Top

 Display posts from previous: All posts1 day7 days2 weeks1 month3 months6 months1 year Sort by AuthorPost timeSubject AscendingDescending
 Page 1 of 1 [ 6 posts ]

 All times are UTC

#### Who is online

Users browsing this forum: No registered users and 5 guests

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

Search for:
 Jump to:  Select a forum ------------------ FORUM RULES    Forum Rules and FAQs 11 PLUS SUBJECTS    VERBAL REASONING    MATHS    ENGLISH    NON-VERBAL REASONING    CEM 11 Plus GENERAL    GENERAL 11 PLUS TOPICS    11 PLUS APPEALS    11 PLUS TUTORS    INDEPENDENT SCHOOLS    11 PLUS CDs/SOFTWARE    11 PLUS TIPS    PRIMARY    SEN and the 11 PLUS    EVERYTHING ELSE .... 11 PLUS REGIONS    Berkshire    Bexley and Bromley    Birmingham, Walsall, Wolverhampton and Wrekin    Buckinghamshire    Devon    Dorset    Essex    Essex - Redbridge    Gloucestershire    Hertfordshire (South West)    Hertfordshire (Other and North London)    Kent    Lancashire & Cumbria    Lincolnshire    Medway    Northern Ireland    Surrey (Sutton, Kingston and Wandsworth)    Trafford    Warwickshire    Wiltshire    Wirral    Yorkshire BEYOND 11 PLUS    Beyond 11 Plus - General    GCSEs    6th Form    University