Q&A - P4 Math

[MrsKiasu]

There are 642 pupils in School A and 840 pupils in School B. The number of boys in both schools is the same.Given that the number of girls in School B is four times that of School A, find the total number of boys in each school.

Sch A : B+G=642
Sch B : B+4G=840

B+4(642-B)=840
3B=1728
B=576 for both school

Now I m worry..is the above method acceptable? Or must use the modelling method (with unit)? The marks will be on the final answer only or workings will also get marks?

[Sharmum]

Hi,

Appreciate if anyone could help with the following question:-

Devi had some bags. She bought 36 red markets, 60 blue markers and 72 black markers. She distributed each set of coloured markers equally into packets without any leftovers.

a) What was the greatest number of packets Devi could pack?
b) How many black markers were there in each packet?

Many thanks!

Red = 36 = 2 x 2 x 3 x 3
Blue =60 = 2 x 2 x 3 x 5
Black=72 = 2 x 2 x 2 x 3 x 3

a) greatest number of packets = 2 x 3 x 3 = 12
b) Black markers = 2 x 3 = 6 in each packet

Sushi88 and Mr Kiasu for your help !

[PiggyLalala]

Alvin had 99 marbles. He gave 24 marbles to Benny and some marbles to Carl. He then had 4/9 of his marbles left.How many marbles did Carl receive?

4/9x99=44 left

Carl gets 99-24-44=31

No 'u'..ok or not ?

No 'u' ok. not every question needs 'u'.

[MrsKiasu]

Alvin had 99 marbles. He gave 24 marbles to Benny and some marbles to Carl. He then had 4/9 of his marbles left.How many marbles did Carl receive?

4/9x99=44 left

Carl gets 99-24-44=31

No 'u'..ok or not ?

No 'u' ok. not every question needs 'u'.

The modelling method..need to draw and use the 'units'? Dunno if that is a must thing to do or as long as could get the final answer then it's OK. .

[PiggyLalala]

There are 642 pupils in School A and 840 pupils in School B. The number of boys in both schools is the same.Given that the number of girls in School B is four times that of School A, find the total number of boys in each school.

Sch A : B+G=642
Sch B : B+4G=840

B+4(642-B)=840
3B=1728
B=576 for both school

Now I m worry..is the above method acceptable? Or must use the modelling method (with unit)? The marks will be on the final answer only or workings will also get marks?

Method is acceptable. But not all p4 child can understand this solution....maybe a bit abstract to some ... first the child needs to know B= 642 - G and then he must know how to substitute it into the second equation. And expand 4 (642 -b)... n finally solve the equation.

I believe the tr will solve this question using model. For this question it is easy to understand using model.

If yr child is weak in model, u may still use yr method but do not use substitution. Tell the child to use the second equation minus the first one. B - B = 0; 4G- G = 3G and
Hence 3G = 840-642...

There are 642 pupils in School A and 840 pupils in School B. The number of boys in both schools is the same.Given that the number of girls in School B is four times that of School A, find the total number of boys in each school.

Given number of boys the same in both school, the difference in pupils must be from girls.

From given, we know that school B has 198 girls more than school A.
Thus,
3u --> 198
1u --> 66

School A has (642 -66) boys.
School B has (840 - (66×4))boys

Nicnac's method is short and sweet.
if the child cant understand why "given number of boys the same in both school means the difference in pupils must be from girls", ask the child to draw the model. It is very easy to understand and solve this question using model.

[MrsKiasu]

There are 642 pupils in School A and 840 pupils in School B. The number of boys in both schools is the same.Given that the number of girls in School B is four times that of School A, find the total number of boys in each school.

Sch A : B+G=642
Sch B : B+4G=840

B+4(642-B)=840
3B=1728
B=576 for both school

Now I m worry..is the above method acceptable? Or must use the modelling method (with unit)? The marks will be on the final answer only or workings will also get marks?

Method is acceptable. But not all p4 child can understand this solution....maybe a bit abstract to some ... first the child needs to know B= 642 - G and then he must know how to substitute it into the second equation. And expand 4 (642 -b)... n finally solve the equation.

I believe the tr will solve this question using model. For this question it is easy to understand using model.

If yr child is weak in model, u may still use yr method but do not use substitution. Tell the child to use the second equation minus the first one. B - B = 0; 4G- G = 3G and
Hence 3G = 840-642...

There are 642 pupils in School A and 840 pupils in School B. The number of boys in both schools is the same.Given that the number of girls in School B is four times that of School A, find the total number of boys in each school.

Given number of boys the same in both school, the difference in pupils must be from girls.

From given, we know that school B has 198 girls more than school A.
Thus,
3u --> 198
1u --> 66

School A has (642 -66) boys.
School B has (840 - (66×4))boys

Nicnac's method is short and sweet.
if the child cant understand why "given number of boys the same in both school means the difference in pupils must be from girls", ask the child to draw the model. It is very easy to understand and solve this question using model.

[Bunny27]

Hi,
I need help to teach my gal on this question.

Kumar and Sumei had 208 stickers altogether at first. After Kumar used 75 stickers and Sumei used 2/3 of her stickers, Kumar had 4 times as many stickers as Sumei. How many stickers did Kumar have at first?

Thank You !

[Future Academy]

Hi,
I need help to teach my gal on this question.

Kumar and Sumei had 208 stickers altogether at first. After Kumar used 75 stickers and Sumei used 2/3 of her stickers, Kumar had 4 times as many stickers as Sumei. How many stickers did Kumar have at first?

Thank You !

Hi Bunny,

Please see the solution in the photo;



Or access this url:
http://www.fa.edu.sg/wp-content/uploads ... 681651.jpg

Cheers!

[Bunny27]

Hi,
I need help to teach my gal on this question.

Kumar and Sumei had 208 stickers altogether at first. After Kumar used 75 stickers and Sumei used 2/3 of her stickers, Kumar had 4 times as many stickers as Sumei. How many stickers did Kumar have at first?

Thank You !

Hi Bunny,

Please see the solution in the photo;



Or access this url:
http://www.fa.edu.sg/wp-content/uploads ... 681651.jpg

Cheers!

Ooh..i understand now.
Thank you~~

[Future Academy]

Hi,
I need help to teach my gal on this question.

Kumar and Sumei had 208 stickers altogether at first. After Kumar used 75 stickers and Sumei used 2/3 of her stickers, Kumar had 4 times as many stickers as Sumei. How many stickers did Kumar have at first?

Thank You !

Hi Bunny,

Please see the solution in the photo;



Or access this url:
http://www.fa.edu.sg/wp-content/uploads ... 681651.jpg

Cheers!

Ooh..i understand now.
Thank you~~

You are welcome. Pls let us know if you need help in Math questions. Our academy centre has ex RGS/NYGH/top schools/GEP maths teachers so we will be glad to help you.

Cheers.