gl paper 11b q 48 help

chelmsford dad · Post by **chelmsford dad** » Thu Oct 15, 2009 9:56 am

sorry cant reproduce the question but basically its the one with 60 squares with 34 shaded grey
each sq is 50cmx50cm and it asks for the total area of the grey shaded squares in metres.
i am just interested in what would be the way to teach the method of arriving at the answer as i got there but unconvincingly!

i put back an imaginary shape together of a 2x17 block therefore the dimensions (2x50cm) * (17x50cm) = 1m*8.5m converted =8.5 sq m which is the answer but...

when i first tried to explain it i did 50cm x 50cm = 2500cm for each sq x 34 = 85,000 cm sq which i couldnt convert down to metres (thought that would make 850m

to get the answer , what am i doing incorrectly in this method?

any help apprecaited thanks

yoyo123 · Post by **yoyo123** » Thu Oct 15, 2009 9:59 am

the answer is given in square metres but the "tiles" are measured in cm.

conversion factor from cm to m is 100 but from square cm to square metres it is 100x 100 (10,000)

chelmsford dad · Post by **chelmsford dad** » Thu Oct 15, 2009 10:03 am

so both methods were ok but i just didnt convert it back properly the second time (havent done these sorts of questions for a long time well thats my excuse

) , which way would you say is better?

yoyo123 · Post by **yoyo123** » Thu Oct 15, 2009 10:20 am

which ever your DC finds easiest to remember!!

gl paper 11b q 48 help

gl paper 11b q 48 help

thanks very much