Q&A - P5 Math

[tianzhu]

panic_mum:

2) Carl and Rose had the same amount of pocket money. Each day, Carl spent $12 and Rose spent $15. When Rose had $18 left, Carl had 5 times as much money as Rose. How much was each child's pocket money?

Hi

One way to look at this question.

Rose @left ------ 18

Carl@left ------- 90 (5*18)

Difference@left ------- 72

Difference spent per day ------ 3 (15-12)

Number of days ------- 72/3 ------- 24

Pocket money@each child ------ 24*12 + 90 ------- 378

Best wishes

[memouse]

Hi, I’m having mental block trying to solve this. Anyone can help to? Thank u so much.


Qn:
Weili used 2 strings of the same length to make 2 necklaces. For the 1st necklace, she used 2 big beads for evey 4 cm of string. For the 2nd necklace, she used 5 small beads for every 3cm of string. She used 84 more small beads than big beads.
a) Find the total number of big beads Weili used.
b) Find the total number of beads Weili used for the 2 necklaces.

[memouse]

Hi, need help to find answer to this qn. Thank u.


Qn:
Mrs Wong had some cookies to give her pupils. If she gave each of them 3 cookies each, she would have 5 left over. If she gave each pupil 4 cookies, she would need 3 more cookies. How many pupils were there?

[cookieandmonster]

Hi, need help in this question. Thank you.


Qn:
The number of books on Shelf Y was 62 more than that on Shelf X. When 31 books were transferred from Shelf X to Shelf Y, the number of books on Shelf Y became 3 times as many as the number of books on Shelf X. How many books were there on Shelf X at first?

[tianzhu]

memouse:

Hi, I'm having mental block trying to solve this. Anyone can help to? Thank u so much.


Qn:
Weili used 2 strings of the same length to make 2 necklaces. For the 1st necklace, she used 2 big beads for evey 4 cm of string. For the 2nd necklace, she used 5 small beads for every 3cm of string. She used 84 more small beads than big beads.
a) Find the total number of big beads Weili used.
b) Find the total number of beads Weili used for the 2 necklaces.

Hi

A common multiple for 4cm and 3cm is 12cm.

For a set of 12cm, there are 6 big beads and 20 small beads.

Difference per set ------ 14

Number of set of 12cm ------- 84/14 ------ 6

Number of big beads ------- 6*6 ------ 36

Total number of beads -------- 6*26 ------ 156

Best wishes

[tianzhu]

memouse:

Hi, need help to find answer to this qn. Thank u.


Qn:
Mrs Wong had some cookies to give her pupils. If she gave each of them 3 cookies each, she would have 5 left over. If she gave each pupil 4 cookies, she would need 3 more cookies. How many pupils were there?

Hi

You may use “SL” or “Excess and Shortage “

In order to give her pupils one more cookie each, Mrs Wong needs 8 (5+3) cookies

Number of pupils ------ 8/1 ------ 8

Best wishes

[tianzhu]

cookieandmonster:

Hi, need help in this question. Thank you.


Qn:
The number of books on Shelf Y was 62 more than that on Shelf X. When 31 books were transferred from Shelf X to Shelf Y, the number of books on Shelf Y became 3 times as many as the number of books on Shelf X. How many books were there on Shelf X at first?

Hi

A neat way is to use MD.

Hope this helps.

Best wishes

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[memouse]

tianzhu:

memouse:

Hi, I'm having mental block trying to solve this. Anyone can help to? Thank u so much.


Qn:
Weili used 2 strings of the same length to make 2 necklaces. For the 1st necklace, she used 2 big beads for evey 4 cm of string. For the 2nd necklace, she used 5 small beads for every 3cm of string. She used 84 more small beads than big beads.
a) Find the total number of big beads Weili used.
b) Find the total number of beads Weili used for the 2 necklaces.

Hi

A common multiple for 4cm and 3cm is 12cm.

For a set of 12cm, there are 6 big beads and 20 small beads.

Difference per set ------ 14

Number of set of 12cm ------- 84/14 ------ 6

Number of big beads ------- 6*6 ------ 36

Total number of beads -------- 6*26 ------ 156

Best wishes

Thanks alot for the solution. Appreciate it.

[memouse]

tianzhu:

memouse:

Hi, need help to find answer to this qn. Thank u.


Qn:
Mrs Wong had some cookies to give her pupils. If she gave each of them 3 cookies each, she would have 5 left over. If she gave each pupil 4 cookies, she would need 3 more cookies. How many pupils were there?

were there?
Hi

You may use “SL” or “Excess and Shortage “

In order to give her pupils one more cookie each, Mrs Wong needs 8 (5+3) cookies

Number of pupils ------ 8/1 ------ 8

Best wishes

Thank u very muchie. :boogie:

My boy used guess and check to solve this:

- 1st;
6x3x5 =23
7x3x5 =26
8x3x5 =29

- 2nd;
6x4x3 =21
7x4x3 =25
8x4x3 =29

Check that answer for 1st and 2nd must be the same, hence the answer is 8. Is this method feasible and ok to use. Thank u

[tianzhu]

memouse:

Check that answer for 1st and 2nd must be the same, hence the answer is 8. Is this method feasible and ok to use. Thank u

Hi

Yes, you may use GC, but it is less efficient at upper primary level as the numbers are bigger.

Let your boy try to use GC for this question.

Mr Chia gives some erasers to his students. If he gives 7 erasers to each student, he will have 53 erasers left. If he gives 9 erasers to each student, he will have 5 erasers left.
(a) How many students does he have?
(b) Find the number of erasers he has at first.

Usually under examination environment, students are hard pressed to finish the questions within tight schedule and a more efficient method would be more advisable.

Best wishes