Q&A - P3 Math

[siti]

Anyone can help? I have one question. Wonder how to explain to my girl.


A + B = 200
A - B = 76

What is A and what is B?

[lizawa]

siti:

Anyone can help? I have one question. Wonder how to explain to my girl.


A + B = 200
A - B = 76

What is A and what is B?

If your daughter can accept solving the 2 equations by adding the right hand side together and equate to the left hand side, then you can do so. After adding : 2A = 276. And you solve for A and B.

If not, use the model.

A+B = 200
______________
|___A___|__B__|

A-B = 76, means one part is 76, the other part is B, the whole figure is A
_________
|_76|_B__|

Then break up the 1st model 'A' into the same \"76\" and \"B\"
you get

76 + B + B = 200

Then solve for B, then solve for A.

[tianzhu]

Hi

Hope this helps.

http://farm4.static.flickr.com/3414/3338039616_a7a248a939_o.jpg\">

[siti]

lizawa:

siti:

Anyone can help? I have one question. Wonder how to explain to my girl.


A + B = 200
A - B = 76

What is A and what is B?

If your daughter can accept solving the 2 equations by adding the right hand side together and equate to the left hand side, then you can do so. After adding : 2A = 276. And you solve for A and B.

If not, use the model.

A+B = 200
______________
|___A___|__B__|

A-B = 76, means one part is 76, the other part is B, the whole figure is A
_________
|_76|_B__|

Then break up the 1st model 'A' into the same \"76\" and \"B\"
you get

76 + B + B = 200

Then solve for B, then solve for A.

Thanks thanks... I think this model is good. I explain to my girl and she understand. But I teach her to write this way

2 units of B -> 200 - 76 = 124
1 unit of B -> 124/2 = 72

A -> 200 - 72 = 128

Thank you. :celebrate:

[Vanilla Cake]

Hi,


Thks for your time and solution for this P4 Maths 5-mark Qn from SCGS SA1 2008 Q42. Pls use model drawings as far as possible & applicable for P4 level :

Library A keeps 50 books more than Library B. If 120 books are transferred to Library B from Library A, there will be twice as many books in Library B as in Library A. How many books are there altogether ?

:salute:

[tianzhu]

Hi,hope this helps.

http://farm4.static.flickr.com/3372/3431668212_9e7aa24b29_o.jpg\">

[Vanilla Cake]

Yes, it helps.

Thank you very much, tianzhu.

:thankyou:

[ChiefKiasu]

tianzhu:

Hi,hope this helps.

http://farm4.static.flickr.com/3372/3431668212_9e7aa24b29_o.jpg\">

Hmm... not sure where you got your 310 + 260 = 570 from. I thought it is simply 190 * 3 = 570?

[small]

ChiefKiasu:

Hmm... not sure where you got your 310 + 260 = 570 from. I thought it is simply 190 * 3 = 570?

Hi ChiefKiasu, hope this help.

tianzhu'ssolution was referred to the model before the transfer.

LA = (1U + 70) + 50 = (190 + 70) + 50 = 310

LB = (1U + 70) = 190 + 70 = 260

Yours was straightforward (after the transfer), 3U = 3 x 190 = 570

[small]

ChiefKiasu:

Hmm... not sure where you got your 310 + 260 = 570 from. I thought it is simply 190 * 3 = 570?

Hi ChiefKiasu, hope this help.

tianzhu'ssolution was referred to the model before the transfer.

LA = (1U + 70) + 50 = (190 + 70) + 50 = 310

LB = (1U + 70) = 190 + 70 = 260

Yours was straightforward (after the transfer), 3U = 3 x 190 = 570