Q&A - P4 Math

[chloecube]

elisammom:

Pls help,


For every 4 beads that A has, B has 2 more beads than her. They have 60 beads altogether. How many beads does B have?

Thanks

A- 4 beads
B - 6 beads
1 group - 10 beads

60/10 = 6 groups
6 x 6 = 36

A - 24
B - 36

[ruohoo97]

Using guess and check method:


Let’s say A has 4, then B will have 6, obviously not equal to 60:
then try the following so on:

A B
4 6 not right
8 10 no
…
till
24 26 no
28 30 then you get 58, so you can conclude that A has 30, while B has 30.

I must say it is not clear whether B has 2 more than very 4 A has, or B has 2 more than A has.=(

[elisammom]

I used the guess and check method but the answer is not right.

The correct answer is 36, just like chloecube done.

I like to know why guess and check method is wrong in this question. Thanks

[elisammom]

Hi another question


24 coins are used to form a square. The number of coins on each side of the square is the same. Find the number of conins on each side of the square.

Ans: 7

Pls help. Thanks

[tianzhu]

elisammom:

Hi another question


24 coins are used to form a square. The number of coins on each side of the square is the same. Find the number of conins on each side of the square.

Ans: 7

Pls help. Thanks

Hi

Perhaps, for questions of such genre, it’s useful to have a simple pictorial representation. It might help to organise your thoughts.

The coins at the 4 corners of the square are counted twice.

24 + 4 ----- 28

28/4 ----- 7

Please study this similar type of question that appeared in the P5 thread.

Hope this helps.

Best wishes

http://farm6.staticflickr.com/5272/6897367566_8d8cd99d93_z.jpg\">

[ruohoo97]

elisammom:

Pls help,


For every 4 beads that A has, B has 2 more beads than her. They have 60 beads altogether. How many beads does B have?

Thanks

If A has 24, B has 36, how can that be B has 2 more beads than her? I can see that

[ruohoo97]

elisammom:

Hi another question


24 coins are used to form a square. The number of coins on each side of the square is the same. Find the number of conins on each side of the square.

Ans: 7

Pls help. Thanks

24 coins put at four coins at four corner of a square, left 20. 20 divide by 4 =5, so each side has 5 coins plus 2 coins at corner=7.

[MathIzzzFun]

elisammom:

Hi another question


24 coins are used to form a square. The number of coins on each side of the square is the same. Find the number of conins on each side of the square.

Ans: 7

Pls help. Thanks

Hi

hope this picture will help to tackle such questions more easily.

http://i44.tinypic.com/ieiiqb.png\">

cheers.

[chloecube]

ruohoo97:

elisammom:

Pls help,


For every 4 beads that A has, B has 2 more beads than her. They have 60 beads altogether. How many beads does B have?

Thanks

If A has 24, B has 36, how can that be B has 2 more beads than her? I can see that

if ruohoo97, if you read it carefully again, For every 4 beads that A has, B has 2 more beads than her

[tianzhu]

elisammom:

I used the guess and check method but the answer is not right.

The correct answer is 36, just like chloecube done.

I like to know why guess and check method is wrong in this question. Thanks

Hi

Yes, you may use GC.

For every 4 beads that A has, B has 2 more beads than her; this means if A has 4 beads, B has 6 beads.

Try it and you should arrive at 24 beads (A) and 36 beads(B).

A common method used by students is “Grouping concept”.

Another way, observe that for every incremental step, there is a difference of 10 beads (total number)

4, 6 ----- 10
8, 12 ------ 20

We are looking for 60.

60 is 6 times as many as 10

Hence multiply initial numbers by 6.

4*6 -----24
6*6 ------ 36

Best wishes