Adrian Ng
Asked 9 years ago

SG chevron_right Primary 6 chevron_right Fractions

Making it visual...

Replies 0

Nisha Alexander
Asked 9 years ago

SG chevron_right Primary 4 chevron_right Fractions

P4 maths question. Please help. Thanks.

Replies 5

Zhong Shu Hao

6 years ago
BA Poh Ann

6 years ago
Nandula Hema

6 years ago
Nisha Alexander

Thanks all for the answers.

6 years ago
Zhong Shu Hao

Ps for my typo...

6 years ago

Tan Lee Kiau
Asked 9 years ago

SG chevron_right Primary 4 chevron_right Number and Algebra

P4~i understd d ans but how to draw models n explain to my kid.John has a total of 40 apples n pears. If he exchanges every pear for 2 apples, he will have 56 apples. How many apples did he have at first? Tia

Replies 8

Chia-Chan Bk

6 years ago
Stacey Tan

6 years ago
Tan Lee Kiau

Thks all.

6 years ago
Sarah Ong

Teachers, I still don't understand...why isn't 12 apples at first? What have I missed out? Please enlighten. Stacey Tan, you illustrated total no of fruit is 56. Not total 56 Apples at the end? A + P=> 40 total 56 / 2 => 28 pears 40-28 = 12 apples (at first)

6 years ago
Stacey Tan

Yes ... All the 56 fruits are apples (since we have exchange all extra pears to apples) We cannot divide 56 / 2 because not all the 56 were pears exchanged for apples. There were already some apples there initially before the exchange.

6 years ago
Stacey Tan

Total number of fruits is 40. According to your answer, you have 12 apples, which means you have (40-12=28 pears). If we change all the pears to apples (28x2=56), then you will have (56+12=68 apples) in the end. But the question says that you only have 56 after the exchange.

6 years ago
Sarah Ong

Ahh...I missed the first step, I'll be misled! Thank you, Stacey Tan.

6 years ago
Sarah Ong

Can't be so simple, right... :D It's good to work backward to counter check answer. Got it!

6 years ago

Tan Lee Kiau
Asked 9 years ago

SG chevron_right Primary 4 chevron_right Number and Algebra

P4 qns need yr help. Thks.Marcus has some marbles. If he gives each friend 6 marbles, he will have 4 marbles left. If he gives each friend 7 marbles, he will be short of 5 marbles. How many marbles does marcus have? Tia.

Replies 23

Zhong Shu Hao

If he gives each friend 6 marbles, he will have 4 marbles left. If he gives each friend 7 marbles, he will be short of 5 marbles. The umber friends increased by 1, yet the demand for marbles increased by 4(left over) + 5(short) =9.

6 years ago
Zhong Shu Hao

So new number of friends = 9/1=9 Marcus will have 9x7-5=58 marbles.

6 years ago
Stacey Tan

6 years ago
Kelene Woo Yan Ling

It's a typical multiples qn which they learnt in p4. They are suppose to present ans in a table form for each multiple. Otherwise qn can be solve with assumption method mentioned above.

6 years ago
Aaron Hee

There is a name to this type of question, commonly known as "Shortage-excess" question.

6 years ago
Tan Lee Kiau

Thks all

6 years ago
Edlynn Rose

6 years ago
Judy Low

Edlynn Rose, for the first method, how do we know when to stop? Why not stop at 16?

6 years ago
Edlynn Rose

well actually, we wouldn't know when to stop unless we work on both concurrently and stop as soon as we see a match.

6 years ago
Judy Low

16 is a match too, right?

6 years ago
Edlynn Rose

as in there are 16 marbles?

6 years ago
Judy Low

Yes. There's a match there. I saw the same method in the assessment book. Similar question asking for number of sweets. They took the first match as the answer.

6 years ago
Judy Low

6 years ago
Stacey Tan

Number of friends must be the same in both multiples. For 16 marbles, you have 2 friends for multiple of 6 and 3 friends for multiple of 7....

6 years ago
Stacey Tan

Like your sweets question, you stop at 6 friends for both multiples of 7 and 8.

6 years ago
Judy Low

Stacey, how about in this case?

6 years ago
Judy Low

I'm sorry. A little confused here.

6 years ago
Stacey Tan

Judy Low, in your question on paper clips, number of bags is not a requirement, which means there is no need to put in the equal number of bags.

6 years ago
Stacey Tan

So she can put in 13 bags of 6 clips and have 3 left or 10 bags of 8 clips and have 1 left. this means that she must have 81 clips in all.

6 years ago
Stacey Tan

In your sweet question, the number of friends is the same whether you give 7 sweets or 8 sweets. It will not be logical if the number of friends changes with the number of sweets you give out.

6 years ago
Judy Low

Ok. So gotta if it's abt giving to friends, must be the same in both multiples since the number of friends is a fixed number?

6 years ago
Stacey Tan

Yes

6 years ago
Judy Low

Ok. Thanks, Stacey Tan!

6 years ago

Emme Wang
Asked 9 years ago

SG chevron_right Primary 4 chevron_right Number and Algebra

Please help to solve this P4 question. Thank you.

Replies 7

Zhong Shu Hao

The total no of marbles do not change. So we only need to find how many marbles there must in A at the end, and then subtract 120 from it.

6 years ago
Zhong Shu Hao

total no of marbles =120+120+260=500 500+238=438 438÷2=219 219-120=99.

6 years ago
Shyamasree Palchaudhury

The coreect ans will be 189

6 years ago
Zhong Shu Hao

will calculate again when i reach hm 😊

6 years ago
Stacey Tan

6 years ago
Ow Yong

Hi Stacey, I like your working steps is a very clear steps to understand.

6 years ago
Yeo See Yeong

6 years ago