## Q&A - P5 Math

### Re: Q&A - P5 Math

Pls help to solve the problem. Thanks.

at an old folks home, the number of residents increased by 15% from 2011 to 2012. however, it decreased by 6% from 2012 to 2013. the number of residents increased by 81 from 2011 to 2013. how many residents were there in 2013?

at an old folks home, the number of residents increased by 15% from 2011 to 2012. however, it decreased by 6% from 2012 to 2013. the number of residents increased by 81 from 2011 to 2013. how many residents were there in 2013?

### Re: Q&A - P5 Math

hweelit wrote:Pls help to solve the problem. Thanks.

at an old folks home, the number of residents increased by 15% from 2011 to 2012. however, it decreased by 6% from 2012 to 2013. the number of residents increased by 81 from 2011 to 2013. how many residents were there in 2013?

2011 to 2012, increase by 15% and it means the number of residents are now 1.15 times compare to year 2011

2012 to 2013, decrease by 6%. It means the number of residents are now 1.15 * 0.94 = 1.081 times compare to year 2011

0.081 --> 81

1.081 --> 1081

Hope this help.

### Re: Q&A - P5 Math

Thank you for the solution. I got the same answer by algebra. I have no idea how a P5 student should solve this by the model method.Brownbear wrote:2011 to 2012, increase by 15% and it means the number of residents are now 1.15 times compare to year 2011hweelit wrote:Pls help to solve the problem. Thanks.

at an old folks home, the number of residents increased by 15% from 2011 to 2012. however, it decreased by 6% from 2012 to 2013. the number of residents increased by 81 from 2011 to 2013. how many residents were there in 2013?

2012 to 2013, decrease by 6%. It means the number of residents are now 1.15 * 0.94 = 1.081 times compare to year 2011

0.081 --> 81

1.081 --> 1081

Is your solution - i.e. the way you wrote it above - acceptable from a student?

I mean specifically this part:

0.081 --> 81

1.081 --> 1081

Or will they be expected to solve this by the model method?

If by the model method, how to solve this problem?

### Re: Q&A - P5 Math

nansk wrote:Thank you for the solution. I got the same answer by algebra. I have no idea how a P5 student should solve this by the model method.Brownbear wrote:2011 to 2012, increase by 15% and it means the number of residents are now 1.15 times compare to year 2011hweelit wrote:Pls help to solve the problem. Thanks.

at an old folks home, the number of residents increased by 15% from 2011 to 2012. however, it decreased by 6% from 2012 to 2013. the number of residents increased by 81 from 2011 to 2013. how many residents were there in 2013?

2012 to 2013, decrease by 6%. It means the number of residents are now 1.15 * 0.94 = 1.081 times compare to year 2011

0.081 --> 81

1.081 --> 1081

Is your solution - i.e. the way you wrote it above - acceptable from a student?

I mean specifically this part:

0.081 --> 81

1.081 --> 1081

Or will they be expected to solve this by the model method?

If by the model method, how to solve this problem?

This is algebra method

Assume u = no. of residents in year 2011

In 2012, there is 1.15u

In 2013, there is 1.081u

Now 0.081u = 81, hence u = 1000

Therefore, 1.081u = 1081

I believe in this question, algebra and model are about the same?

e.g. Define 1000u for year 2011, then 2012 has 1150u and 2013 has 1081u. So 81u = 81 and hence, u = 1

Therefore, 1081u = 1081

Will need expert to help out on model method.

### Re: Q&A - P5 Math

Thanks for your reply.Brownbear wrote:I believe in this question, algebra and model are about the same?nansk wrote: Thank you for the solution. I got the same answer by algebra. I have no idea how a P5 student should solve this by the model method.

Is your solution - i.e. the way you wrote it above - acceptable from a student?

I mean specifically this part:

0.081 --> 81

1.081 --> 1081

Or will they be expected to solve this by the model method?

If by the model method, how to solve this problem?

Will need expert to help out on model method.

I did use the same algebra method as you.

I was wondering how a P5 teacher may teach the student to solve this.

### Re: Q&A - P5 Math

I think your child should be familiar with this method:nansk wrote:Thanks for your reply.Brownbear wrote:I believe in this question, algebra and model are about the same?nansk wrote: Thank you for the solution. I got the same answer by algebra. I have no idea how a P5 student should solve this by the model method.

Is your solution - i.e. the way you wrote it above - acceptable from a student?

I mean specifically this part:

0.081 --> 81

1.081 --> 1081

Or will they be expected to solve this by the model method?

If by the model method, how to solve this problem?

Will need expert to help out on model method.

I did use the same algebra method as you.

I was wondering how a P5 teacher may teach the student to solve this.

2011------>100%

2012------>115%

2013------>108.1%

8.1%------>81

1%-------->10

108.1%------->10x108.1=1081

### Re: Q&A - P5 Math

Thank you! This is helpful.Jx2mum wrote:I think your child should be familiar with this method:nansk wrote: Thanks for your reply.

I did use the same algebra method as you.

I was wondering how a P5 teacher may teach the student to solve this.

2011------>100%

2012------>115%

2013------>108.1%

8.1%------>81

1%-------->10

108.1%------->10x108.1=1081

### Re: Q&A - P5 Math

Can anyone solve this please? Thanks in advance...............

A store sells pens in packs of 2s (small) and 4s (big).

At first there were 3 times more small packs than big packs.

After selling half of the small packs and some big packs, the shopkeeper packs

additional 5 big packs of pens. How many big packs are sold if there are thrice as many small packs as big packs and there is total 300 unsold pens?

A store sells pens in packs of 2s (small) and 4s (big).

At first there were 3 times more small packs than big packs.

After selling half of the small packs and some big packs, the shopkeeper packs

additional 5 big packs of pens. How many big packs are sold if there are thrice as many small packs as big packs and there is total 300 unsold pens?

- milo-cupcake
- OrangeBelt
**Posts:**37**Joined:**Sat Jan 12,

### Re: Q&A - P5 Math

This had been solved before....belnanna wrote:Can anyone solve this please? Thanks in advance...............

A store sells pens in packs of 2s (small) and 4s (big).

At first there were 3 times more small packs than big packs.

After selling half of the small packs and some big packs, the shopkeeper packs

additional 5 big packs of pens. How many big packs are sold if there are thrice as many small packs as big packs and there is total 300 unsold pens?

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