Q&A - P4 Math

[chloecube]

0.2 = 2/10 = 4/20 - food

0.05 = 5/100 = 1/20 - clothes
1/4 = 5/20 - transport

4/20 +1/20 +5/20 =10/20 (spent)
10/20 (saved)

10/20 x 2340 = 1170

[Jamesbond]

http://i46.tinypic.com/2ywzjiw.jpg\">


Pl explain me how to solve it. Thanks in advance.

[Jamesbond]

http://i48.tinypic.com/2iicphz.jpg\">


Pl explain me

[Andaiz]

I can think of a number of ways to solve this question - the most straight forward of which is if the child knows how to find the area of a triangle.


If like mine, they have not learnt 0.5 x l x b as yet, I'll suggest using fractions.

http://i47.tinypic.com/2d7wlk1.jpg\">

Fraction of shaded parts = 5/12.
Area of shaded part = 5/12 X (30 X 14) which is the area of the rectangle
= 175 cm sq.

Hope it makes sense.

[Andaiz]

Jamesbond:

http://i48.tinypic.com/2iicphz.jpg\">


Pl explain me

Hi there,

If the 4 rectagles overlap to form the shadded areas, each square has dimensions = 2X2 cm

16 cm sq/ 4 = 4 cm sq (area)
Length of one side is 2.

Perimeter of Figure A is 36 cm. Length of 1 side is 36/4 = 9cm

Length of one side of P = 9-2(2) = 5
Area of the uncovered portion is 5x5 = 25 cm sq.

[chloecube]

the rectancle of the lenght is 3 times its breadth.

the area of the rectangle is 363cm2. what is the perimeter?

by guess and check, i found the the lenght and breadth is 33 by 11cm. but is there a method to do this other than mine?
cos my method can be rather time consuming.

[MathIzzzFun]

removed

[tianzhu]

chloecube:

the rectancle of the lenght is 3 times its breadth.

the area of the rectangle is 363cm2. what is the perimeter?

by guess and check, i found the the lenght and breadth is 33 by 11cm. but is there a method to do this other than mine?
cos my method can be rather time consuming.

Hi

For this P4 question, it’s not too tedious to use “GC”.

Students are likely to start with an area of 300.

This gives a length of 30 cm and a breadth of 10 cm.

Move forward another step, you’ll get the answer.

An alternative, represent the breadth by 1 unit or 1 box if you prefer MD.

Area of rectangle ----- 1u * 3u

u*u ------ 263/3 ------- 121

From here, u ----- 11 (11*11 = 121,from timetable)

You may continue from here.

Hope this helps.

Best wishes

[chloecube]

tianzhu:

chloecube:

the rectancle of the lenght is 3 times its breadth.

the area of the rectangle is 363cm2. what is the perimeter?

by guess and check, i found the the lenght and breadth is 33 by 11cm. but is there a method to do this other than mine?
cos my method can be rather time consuming.

Hi

For this P4 question, it’s not too tedious to use “GC”.

Students are likely to start with an area of 300.

This gives a length of 30 cm and a breadth of 10 cm.

Move forward another step, you’ll get the answer.

An alternative, represent the breadth by 1 unit or 1 box if you prefer MD.

Area of rectangle ----- 1u * 3u

u*u ------ 263/3 ------- 121

From here, u ----- 11 (11*11 = 121,from timetable)

You may continue from here.

Hope this helps.

Best wishes

noted.
thks once again, Tianzhu

[Jamesbond]

Andaiz:

I can think of a number of ways to solve this question - the most straight forward of which is if the child knows how to find the area of a triangle.


If like mine, they have not learnt 0.5 x l x b as yet, I'll suggest using fractions.

http://i47.tinypic.com/2d7wlk1.jpg\">

Fraction of shaded parts = 5/12.
Area of shaded part = 5/12 X (30 X 14) which is the area of the rectangle
= 175 cm sq.

Hope it makes sense.

Thank you very much. I understood now.