Q&A - P4 Math

[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

[ruohoo97]

Yeh, I see. Thanks a lot!

[chloecube]

Maths is interesting and fun if we can grab the concepts. its challenging and fun solving them

but i find it hard to put it across to my kids sometimes, they dun seem to understand or see it at my level

[elisammom]

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

Thanks tianzhu
Ops I make a cal error;( yes now I see it;)

[Cheerfuldad]

Hi all,


Please help!

Q. There are some chickens and horses at a farm. Altogether, there are 41 heads and 118 leags. How many chickens are there?

TIA

[snowball]

1st step :

find the different ( 4 legs - 2 legs) = 2 legs

2nd step :
assume all 41 heads belongs to the animal that has the lesser no. of legs ie.chickens

thus, 41 heads x 2 legs = 82 legs

3rd step:
118 legs - 82 legs = 18 ( this is the no. of horse )

final step:
41-18=23 ( this is the no. of chickens )

[Mychildren]

Hi, snowball, the third step 118-82 = 36 why is it 18?


Hi, cheerfuldad, I used guess and check:
Chicken21x2=42 Horse20x4 =80 Total heads 41 but legs 122 so not correct.
Chicken22x2=44 Horse19x4=76 Total heads 41 but legs 120 so not correct.
Chicken23x2=46 Horse18x4=72 Total heads 41 and legs 118 so this is the answer.

[snowball]

snowball:

1st step :

find the different ( 4 legs - 2 legs) = 2 legs

2nd step :
assume all 41 heads belongs to the animal that has the lesser no. of legs ie.chickens

thus, 41 heads x 2 legs = 82 legs

3rd step: sorry, overlooked a step
118 legs - 82 legs = 36
36 divide by the difference ie = 2 , to get 18 ( this is the no. of horse )

final step:
41-18=23 ( this is the no. of chickens )

i used to use \"guess n check\" method, but sometimes my girl failed to get the correct guess even after the 4th or 5th attempt, so i switched to the above method :imcool: