Q&A - P5 Math

[tianzhu]

Mr zaini has a carton containing some red n green apples. If he add 10 red apples, 0.6 of the no
Of apples in the carton will be green apples. If he adds in 30 green apples, 3/4 of the no
Of apples will be green apples. How many apples are there in the carton.

Ans 90

Hi muska

Good Afternoon.

You may take a look at this similar question.

Hope this helps.

Best wishes

[happyheart]

DS is rather weak at this type of questions, with unknown in the beginning. Could someone help to explain in a simple term? Thank you!

A shop owner sold 175 T shirts. He donated 1/9 of the remaining T shorts to a charitable organisation. He had 4/7 of the Tshirts left.
a) What fraction of the Tshirts was sold?
b) How many Tshirts had he at first?

[alderbaran]

DS is rather weak at this type of questions, with unknown in the beginning. Could someone help to explain in a simple term? Thank you!

A shop owner sold 175 T shirts. He donated 1/9 of the remaining T shorts to a charitable organisation. He had 4/7 of the Tshirts left.
a) What fraction of the Tshirts was sold?
b) How many Tshirts had he at first?

[Swift Formula]

You can't see the connection between the model and the algebra?

Why should I and why the need to??

Model is almost the same as algebra.
1 unit = 1a = a

[happyheart]

DS is rather weak at this type of questions, with unknown in the beginning. Could someone help to explain in a simple term? Thank you!

A shop owner sold 175 T shirts. He donated 1/9 of the remaining T shorts to a charitable organisation. He had 4/7 of the Tshirts left.
a) What fraction of the Tshirts was sold?
b) How many Tshirts had he at first?

Thank you for the solution!

[tanxexy]

Please help on this question from ACS P5 2014 SA2:

[tianzhu]

Please help on this question from ACS P5 2014 SA2:

Hi tanxexy

Good Afternoon

I suggest you get hold of a piece of paper and fold according to picture (no need to be same as dimensions).

This is to get your kid to understand the concept of folded areas or angles.

For this question, imagine you unfold the triangles at the left and right sides to form a square piece of paper of 12cm by 12cm.

Shade the original triangles with colours if you want to.

On the lower side of the square, you’ll see three equal sides of 4cm (12/3).

12 – 5 ----- 7

Area of 1 triangle ----- ½*4*7

Area of 4 triangles ----- ½*4*7*4 ----- 56

Area of square ----- 12*12 ----- 144

Area of shaded parts ----- 144 – 56 ----- 88

Hope this helps.

Best wishes

[Ice watch]

Please help on this question from ACS P5 2014 SA2:

x=3.96 <---------------【refer to the picture below】
2*3.96*7 = 55.44 <---【4 triangles area】
12*12 = 144 <---------【square area】
144 - 55.44 = 88.56 cm^2 【 the total area of the shaded part 】

[SAHMom]

Please help on this question from ACS P5 2014 SA2:

x=3.96 <---------------【refer to the picture below】
2*3.96*7 = 55.44 <---【4 triangles area】
12*12 = 144 <---------【square area】
144 - 55.44 = 88.56 cm^2 【 the total area of the shaded part 】

Hi, just a note in case there is any panic mode activated. The above solution pricked my interest due to its complexity and I think Ice Watch has proven the exact dimensions and areas using Pythagoras' Theorem (PT). But as P6 are not expected to learn and use the PT, I would like to think that the question might have been overlooked by the setter and it is not his/her initial intention to have the solution using the PT. I made a 12cm by 12 cm paper and did like the folding and the bottom edge did look exactly like cut into 3 equal parts of 4cm. As a parent of P6 kid, I would just point out the error to the teacher but will not go beyond the classroom and teach my kid on the above. At most, I will rephrase the question to finding "an estimate" of the shaded area and use TianZhu's working earlier if I really want my P6 kid to solve it.

[Ice watch]

Please help on this question from ACS P5 2014 SA2:

x=3.96 <---------------【refer to the picture below】
2*3.96*7 = 55.44 <---【4 triangles area】
12*12 = 144 <---------【square area】
144 - 55.44 = 88.56 cm^2 【 the total area of the shaded part 】

Hi, just a note in case there is any panic mode activated. The above solution pricked my interest due to its complexity and I think Ice Watch has proven the exact dimensions and areas using Pythagoras' Theorem (PT). But as P6 are not expected to learn and use the PT, I would like to think that the question might have been overlooked by the setter and it is not his/her initial intention to have the solution using the PT. I made a 12cm by 12 cm paper and did like the folding and the bottom edge did look exactly like cut into 3 equal parts of 4cm. As a parent of P6 kid, I would just point out the error to the teacher but will not go beyond the classroom and teach my kid on the above. At most, I will rephrase the question to finding "an estimate" of the shaded area and use TianZhu's working earlier if I really want my P6 kid to solve it.

Fully agree w u SAHMom. The Q itself is something "wrong", cos theoretically the bottom triangle is not an ideal "equilateral triangle". And these verification stuff is definitely beyond of the pri. scope.... too bad.