Q&A - P3 Math

[Tang]

Dignity:

ChiefKiasu:

From Ai Tong Pri 3 SA1 Maths:


A teacher gave her students some balloons. If she gave 6 balloons to each student, she will have 2 balloons left. If she gave 8 balloons to each student, she will be short of 2 balloons. What is the smallest possible number of students she has?

Try to do this without using ALGEBRA!

Excess+Shortage
______________ = No. Of Students
Difference

So,

2+2=4
4/2=2

So, the answer is 2.

Hi,

2 + 6 = 8

1 --> 8
2 --> 14

- 2 + 8 = 6

1 --> 6
2 --> 14 (matched above number of balloons)

So there are 2 students.

[peggy]

Please help me with the following P4 qtn.



24 guavas and 130 oranges in a basket had a mass of 10.27 kg. When 5 guavas and all the oranges are taken out, the mass became 4.07 kg. Each guava has a mass 5 times as much as each orange. Find the mass of the basket when it is empty, in grams.


Thanks!

[tianzhu]

Hi


Hope this helps.

Best wishes.

http://farm5.static.flickr.com/4125/5088021525_3d1b333942_b.jpg\">

[match3frog]

Pl help with this P4 question. I’ve got the answer but don’t know how to explain to dd:


There are a total of 28 chickens and cows in a farm. If the total number of cows’ legs is 40 more than the total number of chickens’ legs, find the number of chickens and cows in the farm.

Thanks!

[teachingmum]

Hi, you may like to try the Guess and Check Method. This is a rather easy method which the younger or weaker pupils like…


No of Cows No of chickens Total no of cows’ legs Total no of chickens’ legs Difference

14 14 56 28 28
15 13 60 26 34
16 12 64 24 40 *


There are 16 cows and 12 chickens in the farm.[/list]

[teachingmum]

Hi, you may like to try the Guess and Check Method. This is a rather easy method which the younger or weaker pupils like…


No of Cows/ No of chickens/ Total no of cows’ legs/ Total no of chickens’ legs/ Difference

14 14 56 28 28
15 13 60 26 34
16 12 64 24 40 *


There are 16 cows and 12 chickens in the farm.[/list]

[tianzhu]

Hi


Besides Guess and Check, you may also use a problem solving heuristics called Make a Supposition or Assuming method.

Hope this helps.

Best wishes.

http://farm5.static.flickr.com/4088/5092600515_9cc75f1dac_b.jpg\">

[match3frog]

Thanks so much teaching mum and tianzhu!


dd can do the guess and check method but I want her to learn the other method by tianzhu.

Tianzhu, thanks alot for the nice illustration!

[tianzhu]

match3frog:

Tianzhu, thanks alot for the nice illustration!

Hi

You're welcome.

Best wishes

[tinasen]

Samy had 4 times money that of Mary at first. After Samy gave $45 to Mary, both of them had equal amount of money. How much did Mary have at first? Please help to solve this by model method. I tried to understand the answer key that was given to my son, but not very sure how 3u is equated to 45.