Primary 6 maths problems.

• likeyou

  2 May 10, 10:07

  Hi Everybody

   

  Please help me with this problems.

  I am unable to do and confused.

   

  1) Mr Lee has 520 more pens than erasers in his shop. 1/3 of the number of pens is equal to 3/4 of the number of erasers. He packes all the pens into boxes. If there are 16 pens in a box, how many boxes does Mr Lee need?

   

  2) Jack bought CDs at $5 each and sold them at $8 each. To promote sales, all customers who bought 2 CDs were given 1 free CD. After he had sold all his CDs, Jack made a profit of $660 despite giving away 120 CDs to his customers. How many of Jack's customers bough only 1 CD?

   

  Thanks so much for your time and explanation.

  I waiting for everybodys reply.

   

  Cheers.

   

  @LikeYou.

  :)

   

   

• phil@

  2 May 10, 10:54

  Q1    have your learned simultaneous equations?

     let x be the number of pens.

     let y be the number of erasers.

    x-y=520

    1/3 x=3/4y

  solve these two equations simultaneously.

  x=520+y

   then 1/3(520+y)=3/4y

  hence y=416

       x=936

  936/16=58.5

     therefore he needs 59 boxes.

• dibilo

  2 May 10, 11:06

  http://yfrog.com/2oslide1zsj

  http://yfrog.com/0islide2kj

• baiyun

  2 May 10, 11:11

  Hi

  Hope this helps.

  Best wishes

  

• Lubb-Shhh-Dubb

  2 May 10, 12:36

  When i first learnt algebra, the first thing that came to my mind was "Thank goodness! no more drawing silly rectangular models!" In my infinite wisdom... I educated my little brother how to use algebra when he was in primary 3.  Which resulted in a lengthy debate with his maths teacher.

   

  Algebra is like magic.  Its really really really useful. But it seriously kills understanding =) 

• jayh272416

  2 May 10, 12:41

  model method is bullshit.

  honestly i find that model method is just algebra in diagrams. as you can see from the example above. its equating both values in terms of units and finding out the value of 1 unit. lol.

• likeyou

  2 May 10, 13:52

  Hi Phi, Bai, Lub and Jay,

   

  Thanks very very much for your time and help.

  I will impart your solving to my kid.

  Hope my kid know.

   

  I might have other problems that need your help too.

   

  Many many thanks for your help again.

   

  @LikeYou.

• wee_ws

  2 May 10, 20:22

  Originally posted by jayh272416:

  model method is bullshit.

  honestly i find that model method is just algebra in diagrams. as you can see from the example above. its equating both values in terms of units and finding out the value of 1 unit. lol.

  Hi,

    Children at the primary level are concrete learners, so they are learning aspects of algebra via the model method. Hope that clarifies. Thanks.

  Cheers,
  Wen Shih

• -StarDust-

  2 May 10, 23:32

  wah nowadays maths so hard .

   

• likeyou

  3 May 10, 09:16

  Hi Everybody, I really have a hard time teaching my kids. The problems is so difficult and my kids also had a hard time to understand.

   

  Thanks to everybody that I need help as you guys really explain it in simplfied form.

   

  Thanks again everybody for your help.

   

  @LikeYou.

• wee_ws

  3 May 10, 10:29

  Hi likeyou,

    Help your child to improve on comprehension skills, so that he/she will be able to translate words into mathematical details. Jiayou!

  Cheers,
  Wen Shih

• likeyou

  3 May 10, 16:13

  Thanks Wee for your encouragement.