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Mental arithmetic book 6 - schofileds&sims
Posted: Mon Sep 20, 2010 10:11 am
by WorriedRuby
Hi,
did anyone work out the section 1 Test 3 question 'c' (bookcase) ? if yes, can you tell me the answers please.
thanks
Re: Mental arithmetic book 6 - schofileds&sims
Posted: Mon Sep 20, 2010 10:19 am
by yoyo123
i haven;t got the book, but if you type the question on here i am sure someone can help you work it out
Re: Mental arithmetic book 6 - schofileds&sims
Posted: Mon Sep 20, 2010 11:09 am
by DIY Mum
Answers:
1) £7.50 as he needs to buy 3 planks of wood which are £3 each per 250 cm length.
2) Total planks for 2 sides are 1 (each side of his bookcase is 110cm height- plank length available is 250cm)
3) Planks needed for top, bottom and shelves are 2. Total length of shelves is 55 x 5= 275cm, so he needs to buy 2 planks.
4) Total no. of planks to make bookcase is therefore 3. Using info from q2 and q3.
5) Total cost to buy all wood needed to make bookcase is £22.50.
6) How wide will the bookcase be, allowing for the thickness of the sides? 59cm (55 + 4cm).
7) Total length of shelves on which books can be placed is 220cm (i.e 4 x 55cm excluding top shelf)
If shelves are evenly placed, size of tallest book will be 25cm (110-10)/4 cm: each plank is 2cm thick.
9) How many 25 mm books will fit on each shelf? 22 books. (Shelf length is 55cm. Convert into mm: 550 /25)
10) 88 books to fit whole bookcase. (22 x 4)
11) Total length of wood used to make bookcase 495cm (110x2) + (5 x 55)
12) Left over wood 255cm (750-495)
Re: Mental arithmetic book 6 - schofileds&sims
Posted: Mon Sep 20, 2010 11:41 am
by WorriedRuby
Thank you very much DIY mum!
I will have to wait see who wins (DS or DH).
Re: Mental arithmetic book 6 - schofileds&sims
Posted: Mon Sep 20, 2010 7:22 pm
by WorriedRuby
Hi DIY mum,
re answer for the first question - we think it should be 75p as each plank is 250cm long and it costs £3.oo per meter length, so cost of one plank will be £3.00/4 ( as 250cm is 1/4 of 1 meter)
Re: Mental arithmetic book 6 - schofileds&sims
Posted: Mon Sep 20, 2010 8:47 pm
by stevew61
WorriedRuby wrote:Hi DIY mum,
re answer for the first question - we think it should be 75p as each plank is 250cm long and it costs £3.oo per meter length, so cost of one plank will be £3.00/4 ( as 250cm is 1/4 of 1 meter)
250cm is 2.5M, 25cm would be a quarter metre.
100cm=1M 10mm=1cm so 1000mm=1M, easy to get confused.
I have had fun trying to give DCs an appreciation of imperial units, they just don't get it!
Re: Mental arithmetic book 6 - schofileds&sims
Posted: Mon Sep 20, 2010 9:26 pm
by WorriedRuby
Hi stevew61 and DIY mum,
YES! you are both right! still don't believe we made such a silly mistake
(
))
Re: Mental arithmetic book 6 - schofileds&sims
Posted: Tue Sep 21, 2010 7:55 pm
by DIY Mum
Don't worry about silly mistakes...I just made one today with my daughter.
The question was: if 2/3 of a number is 16 what is 3/4 of the number? Silly me was dividing by 3 instead of 16/2 to get 1/3 of the number: gives (8) which times by 3 reveals that the number is 24!! Thankfully, my daughter was awake and told me how to do it...I was so embarrassed!!
Re: Mental arithmetic book 6 - schofileds&sims
Posted: Sat Nov 09, 2013 7:15 pm
by krishnyxx
can you tell me the answers to section 2 test 2 please my daughter very troubled thank you
Re: Mental arithmetic book 6 - schofileds&sims
Posted: Sat Nov 09, 2013 7:17 pm
by krishnyxx
plz can you help my daughter she needs the answers for section 2 test 3