Q&A - P4 Math

[chokos]

@ Tianzhu

Thank you very much.

[usaik]

MathIzzzFun:

Hi

Find the common factors for 102 and 54...

54 = 1 x 2 x 3 x 3 x 3 = 6 x 9
102 = 1 x 2 x 3 x 17 = 6 x 17

Since each side of W is a whole number, each side = 6 cm, area = 36 cm2
So, area of V = 17 x 9 = 153 cm2
V-W= 153 - 36 = 117 cm2

cheers.

Hi MathIzzzFun,
Thank you for the working!
Regards.

[MathIzzzFun]

usaik:

MathIzzzFun:

Hi

Find the common factors for 102 and 54...

54 = 1 x 2 x 3 x 3 x 3 = 6 x 9
102 = 1 x 2 x 3 x 17 = 6 x 17

Since each side of W is a whole number, each side = 6 cm, area = 36 cm2
So, area of V = 17 x 9 = 153 cm2
V-W= 153 - 36 = 117 cm2

cheers.

Hi MathIzzzFun,
Thank you for the working!
Regards.

u r welcome

cheers.

[pineapple tarts]

hello, can someone help with this pls


Ali has 3 times as many stickers as Mohan. If Ali gives 165 stickers to Mohan, he will have ½ as many stickers as Mohan. How many stickers do they have altogether?

Many thanks in advance.

[PiggyLalala]

One possible approach: Using units and parts:

A: M = 3u : 1u = 9u: 3u
A: M = 1p : 2p = 4p: 8p
Total remains the same:
Therefore 12u = 12p, that is u = p
Therefore (before) A:M = 9u:3u
(after) A: M = 4u:8u
Therefore 5u = 165
u= 33
Total = 12u = 396 stickers

[usaik]

Another possible approach would be using model as below :

http://i54.tinypic.com/rbjxh3.jpg\">

[Jenlimtz]

Hi


Need help:

1) Farmer Lim sold 1/2 as many eggs on Saturday than on Friday. He sold 78 less eggs on Sunday than on Friday. If he sold a total of 172 eggs on the three days, how many eggs did he sell on Sunday?

2) Tin A contains some 20-cents coins and Tin B contains some 50-cents coins. There are 9 more coins in Tin A than in Tin B. The amount of money in Tin A is $2.70 less than that in Tin B.
How many 50-cents coins are there in Tin B?

TIA

[pineapple tarts]

many thanks to piggylalala and usaik. I need some time to digest the solution. I am seeing stars . . .

[pineapple tarts]

I cannot figure out why 165 is 5 units. let me think let me think . . .

[tianzhu]

Jenlimtz:

1) Farmer Lim sold 1/2 as many eggs on Saturday than on Friday. He sold 78 less eggs on Sunday than on Friday. If he sold a total of 172 eggs on the three days, how many eggs did he sell on Sunday?

2) Tin A contains some 20-cents coins and Tin B contains some 50-cents coins. There are 9 more coins in Tin A than in Tin B. The amount of money in Tin A is $2.70 less than that in Tin B.
How many 50-cents coins are there in Tin B?

Hi

Q1) You may use MD.

Fri ------ 2 units
Sat ----- 1 unit
Sun ------ 2 units – 78

2 units + 1unit + (2units – 78) ------172

5 units ------ 250
1 unit ------50

Number of eggs sold on Sun ----- (2*50) – 78 ------22.



Q2) Suppose or pretend that you remove 9 20 cents coins from Tin A.

9*20 ---- 180

Now Tin A has (270+180) or 450 cents less than Tin B

Difference in value between a 50 cents coin and 20 cents coin ------ 30 cents.

450/30 ------ 15

There are 15 50 cents coins in Tin B.

Best wishes