## Q&A - PSLE Math

- speedmaths.com
- BrownBelt
**Posts:**559**Joined:**Mon Oct 12,**Total Likes:**3

### Re: Q&A - PSLE Math

Hi Jerico,Jerico wrote:Hi speedmaths,

Thank you so much for your solution.

However, as I'm not familiar with the bags and boxes method, can you please advise how you get 3 bags and 4 boxes = 34 and 1 bag and 1 box = 10 ?

Or is there any other way to solve this problem by making use of the percentage ? (sorry, forgot to mention that this worksheet is to test students on percentage concept)

Tks

speedmaths.com wrote:Jerico wrote:Hi, Can someone please help with the following question :-

Q : There were a total of 34 puppies and kittens at Kenneth's Animal Shelter. After 2/3of the puppies and 75% (or 3/4) of the kittens were adopted, 10 puppies and kittens were left at the animal shelter. How many kittens were at Kenneth's Animal Shelter at first ?

Thank you in advance for your help !

At first:

3Bags (Puppies) +4Boxes (Kittens) -> 34 ....(Row 1)

Finally:

1 Bag + 1 Box -> 10

(× 3)

3 Bags + 3 Boxes -> 30.................(Row 2)

Row 1 - Row 2

0 Bag + 1 Box -> 34 - 30 = 4

4 Boxes -> 4 × 4 = 16 (Kittens).

Hope this helps.

Cheers

SpeedMaths

.

let's try again.

Look at the two denominators;

**3**and

**4**.

**At first**:

Let there be

**3**Bags of Puppies.

Let there be

**4**Boxes of Kittens.

(There were a total of 34 puppies and kittens)

3 Bags (Puppies) + 4 Boxes (Kittens) → 34 ....(Row 1)

**Changes**:

2/3 (or 2 Bags) of the puppies were adopted

75% (or 3 Boxes) of the kittens were adopted

**Left**:

1/3 (or 1 Bag) of the puppies were left

25% (or 1 Box) of the kittens were left

(10 puppies and kittens were left)

1 Bag + 1 Box → 10

(× 3)

3 Bags + 3 Boxes → 30............................(Row 2)

Row 1 - Row 2

0 Bag + 1 Box → 34 - 30 = 4

1 Box → 4

4 Boxes → 4 × 4 = 16 (Kittens at first)

Hope this helps.

Cheers

**SpeedMaths**

.

### Re: Q&A - PSLE Math

I didn't know bag and box is also simultaneous eqn,, Always learning something new.John Lim wrote:Bags and boxs method = simultaneous equations

### Re: Q&A - PSLE Math

Total chris gave to Jon and molly25 +31=56Daddy wrote:Hi.

Please help on these 2 questions. Thank.

Thank..

And this amount of transfer makes (Jon and Molly) twice of Chris.

JM:C =>2:5 => 6u:15u

After tranfer, JM is twice of C. 8u transfer would meet this criteria

JM2:C2 => 14u:7u

8u= 56, u=7

JM2=14u=98, J3 would be 98/2 = 49 units.

Jon at first is 49+12 - 25 = 36 sweets

### Re: Q&A - PSLE Math

Hi, I need help with the following 2 questions:

1) Henry, Ivan and Jack bought a present for their father.

Henry paid 2/3 of the total amount paid by Ivan and Jack.

Ivan paid 2/3 of the total amount paid by Henry and Jack.

If Jack paid $45 more than Ivan, how much did the present cost?

2) In January, the ratio of number of boys to the number of girls in the choir was 7:4. By October, 12 girls wer replaced by 12 boys.

The ratio of the boys to girls in the choir then became 1:2.

How many boys were in the choir in January?

Greatly appreciate. Thanks

1) Henry, Ivan and Jack bought a present for their father.

Henry paid 2/3 of the total amount paid by Ivan and Jack.

Ivan paid 2/3 of the total amount paid by Henry and Jack.

If Jack paid $45 more than Ivan, how much did the present cost?

2) In January, the ratio of number of boys to the number of girls in the choir was 7:4. By October, 12 girls wer replaced by 12 boys.

The ratio of the boys to girls in the choir then became 1:2.

How many boys were in the choir in January?

Greatly appreciate. Thanks

- speedmaths.com
- BrownBelt
**Posts:**559**Joined:**Mon Oct 12,**Total Likes:**3

### Re: Q&A - PSLE Math

Hi Ender,Ender wrote: I didn't know bag and box is also simultaneous eqn,, Always learning something new.

See also my post on Maths Assessment Books (Page 81),

(Posted: 19 Apr 2013 04:04)

=

**Model Method and Algebra**

The Singapore Model Method (used in our primary schools) is essentially "Algebra in pictorial form".

Algebra simply present the "Model Method in abstract/algebraic form".

The Model Method is used as a sort of "pre-algebra", as young children are better able to handle/understand pictorial forms than abstract forms. They will switch more to algebra when they are in secondary school.

The

**Advanced Model Method**uses "Double Models" or "

**Bags and Boxes**" or "Ovals and Rectangles" to solve ALL P5 and P6 maths questions involving "

**2 pairs of ratios**".

It can also be used to solve many other maths problems involving fractions, ratios and percentages.

Alternatively, students may also use the more algebraic methods, using

**"units" and "parts"**, or "u" and "p".

The "u" and "p" are essentially just like the "x" and "y" commonly used in secondary school algebra.

Hope this helps.

**SpeedMaths**

=

- acehkr3009
- OrangeBelt
**Posts:**42**Joined:**Tue Mar 24,

### Re: Q&A - PSLE Math

Hi... please help with this question. Thanks in advance

Some beads are packed into packets of 5 or 7. If the ratio of the number of packets to the number of beads is 5:29. What fraction of the packets contain 7 beads?

Some beads are packed into packets of 5 or 7. If the ratio of the number of packets to the number of beads is 5:29. What fraction of the packets contain 7 beads?

- acehkr3009
- OrangeBelt
**Posts:**42**Joined:**Tue Mar 24,

### Re: Q&A - PSLE Math

Hi, please help with this question. Thanks in advance.

Some beads are packet into packets of 5 or 7. If the ratio of the number of packets to the number of beads is 5:29, what fraction of the packets contain 7 beads?

(1) 1/5 (2) 2/5 (3) 3/5 (4) 4/5

Some beads are packet into packets of 5 or 7. If the ratio of the number of packets to the number of beads is 5:29, what fraction of the packets contain 7 beads?

(1) 1/5 (2) 2/5 (3) 3/5 (4) 4/5

### Re: Q&A - PSLE Math

Hi acehkr3009acehkr3009 wrote:Hi, please help with this question. Thanks in advance.

Some beads are packet into packets of 5 or 7. If the ratio of the number of packets to the number of beads is 5:29, what fraction of the packets contain 7 beads?

(1) 1/5 (2) 2/5 (3) 3/5 (4) 4/5

Good Morning.

Draw five circles to show the number of packets of beads.

Next, come to the number of beads.

Use number bonds, 29 ----- 15 + 14, therefore 5+5+5+7+7

Hence two out of five circles show 7 beads.

This gives an answer of 2/5.

Hope this helps.

Best wishes

### Re: Q&A - PSLE Math

Thank Ender for the working and answer.

But I am not understand how did you get JM twice than C...on wards . Thanks.

But I am not understand how did you get JM twice than C...on wards . Thanks.