chloecube:

thks Swift Formula

but how do i explain to a P4 kid who has not touch algrebra before?

a = 1 unit
5a = 5 units ...
I'm sure every student touched units and models .

algebra is to remove the need of drawing models .

son = a years old

Mrs Chong = 5a years old
5a + 12 = 3(a+12)
5a + 12 = 3a + 36
a = 12
5a = 60

Ender:

kkesavan:

http://i60.tinypic.com/kams74.jpg\"> Hi,


Please help with the following questions.

(4)

Assuming the missing angle is an right angle .
Answer will be (3) v and z ?

Assuming the missing angle is not an right angle .
If (4) y and z is 90 deg, (2) w and y is also 90 deg .
There's only 1 correct answer so both (2) and (4) are wrong .
^ Logical deduction .

squishybuns:

:thankyou: :thankyou:

Swift Formula:

Welcome . 1 more month to PSLE .

squishybuns:

2) There were some blue and pink beads in a box. After Lilian added 30 more blue beads into the box, 4/7 of the beads in the box were pink beads. Next, she added 35 more pink beads. The percentage of the pink beads then became 60%. How many blue and pink beads were there in the box at first?

B + 30 = 3/7 (B+P)
0.6 (B + 30) = 0.4 (P + 35)
2 equation 2 unknowns. Hence solved.
B = 360 , P = 550

squishybuns:

Hi. Pls help!!


1) Ryan had some 20c, 50c and $1 coins. The value of the 20c ,50c and $1 coins was in the ratio of 5 : 21 :15. After Ryan spent 98 of the 20c coins and 4/7 of the 50c coins, he had $270.40 left. What percentage of the coins left was 50c coins.
(Give ans correct to 2 decimal places)

25 : 42 : 15
(let it be 25a : 42a : 15a)
25a - 98 x 0.2 + 18a x 0.5 + 15a = 270.4
5a + 9a + 15a = 270.4 + 19.6
29a = 290
a = 10
Leftover 20 : 50 : 100
= 250-98 : 180 : 150
=152 : 180 : 150
180/482 x 100% = 37.34%

alfretztay:

\"Edward and Freddy began running from point X to point Y at 8am. The average speed of Edward and Freddy were 15km/h and 27km/h respectively. After running for 40 min, Freddy turned back and ran towards Edward. Freddy ran past Edward when he was at the mid-point between the two points. At what speed must Edward run to reach point Y at 9.30am?\"

As the above question still receives no reply since it was last posted on Mon Jul 27, 2015 11:19 pm, I am re-posting it now.

12 x 2/3 = 8 km
8 / 42 = 80/7 minutes
40 + 80/7 = 360/7 minutes = 6/7 hours
6/7 x 15 = 90/7 km
90/7 / (3/2 - 6/7) = 20 km/h

Hence solved .

Well every student has their own interpretation of the question and should try multiple methods.

PSLE markings is based on understanding of the question .


If his/her workings and methods can solve the question and have proof of understandings, it will be accepted .

Model is encourage to help students to visualise only .

angel:

Thank you very much!

Welcome . :rahrah: