Q&A - P4 Math

[tianzhu]

chloecube:

Tim has 336 local and foreign stamps at first. He gave away 2/5 of the local stamps and 46 foreign stamps. He then found that he had 3/5 as many local stamps as foreign stamps left. How many foreign stamps did he have at first?

Hi

You may use MD

Local
Gave ------- 2 units
Left ------ 3 units

Foreign
Gave ------ 46
Left ------ 5 units

10 units + 46 ------- 336
10 units ------ 290
1 unit ------- 29

Foreign stamps @first ------ (5*29) + 46 ------- 191

Best wishes

[chloecube]

Thks for fast reply tianzhu

[Tresille]

Hi, need your assistance.


John has a total of 20 apples and pears. If he exchanges every pear for 2 apples, she will have 28 apples. How many apples and pears does he have? Can we use model drawing to solve this qn?

[Zack7]

Tresille:

Hi, need your assistance.


John has a total of 20 apples and pears. If he exchanges every pear for 2 apples, she will have 28 apples. How many apples and pears does he have? Can we use model drawing to solve this qn?

let x be pears
let y be apples

x + y = 20
2x + y = 28

20-x = 28 -2x
x = 8 pears
y = 12 apples



it is possible to use models to solve this question
but you have to do it to scale. or have a relative scale
like 1cm to 1 unit. but it is not an efficient way to do this sort of questions.

in fact , i just need to use logic to be able to solve this question. logic is the best approach for simple cases like these.
if 1 pear becomes 2 apples, then that would mean every pear i change to apple will yield me a net of +1

so if i have 28 as a new total, where did the 8 extra came from? it would mean i have a net of +8. then, it would mean i have changed 8 pears.

if i had 38 as a new total, it would mean 38-20 = 18, which means i have changed 18 pears and so on...

[rrjan]

Can somebody kindly help me to solve this sum using the internal transfer method? Kindly show me how to draw the models. Thanks


Qn 1) Imran had 4 times as much money as Lucy. After Imran had given Lucy $210, they had an equal amount of money left. How much did each of them have at first?

[CRAZYBANANA]

Can somebody kindly help me to solve this sum using the internal transfer method? Kindly show me how to draw the models. Thanks


Qn 1) Imran had 4 times as much money as Lucy. After Imran had given Lucy $210, they had an equal amount of money left. How much did each of them have at first?

Imran = 4u
Lucy = 1u
4u - 210 = 1u + 210
3u = 210 + 210
1u = 420 / 3 = 140
Imran = 4u = 4x140 = 560
Lucy = 1u = 140

[Xiao Hu]

Zack7:

Tresille:

Hi, need your assistance.


John has a total of 20 apples and pears. If he exchanges every pear for 2 apples, she will have 28 apples. How many apples and pears does he have? Can we use model drawing to solve this qn?

let x be pears
let y be apples

x + y = 20
2x + y = 28

20-x = 28 -2x
x = 8 pears
y = 12 apples



it is possible to use models to solve this question
but you have to do it to scale. or have a relative scale
like 1cm to 1 unit. but it is not an efficient way to do this sort of questions.

in fact , i just need to use logic to be able to solve this question. logic is the best approach for simple cases like these.
if 1 pear becomes 2 apples, then that would mean every pear i change to apple will yield me a net of +1

so if i have 28 as a new total, where did the 8 extra came from? it would mean i have a net of +8. then, it would mean i have changed 8 pears.

if i had 38 as a new total, it would mean 38-20 = 18, which means i have changed 18 pears and so on...

Hi Tresille,
For P4 level and for this question, other than Guess & Check strategy/method, can use the Supposition/Supposition & Tabulating & look-for-a-pattern strategy. Please see page 48 on one of post by Tianzhu. You can search \"\"4)There were 50 children in Xie Ming Ming’s party\". Tianzhu had given quite a lot of such questions with solutions thrown in. I encourage you to take a look.

Hope it helps.
XiaoHu.

[MathIzzzFun]

Tresille:

Hi, need your assistance.


John has a total of 20 apples and pears. If he exchanges every pear for 2 apples, she will have 28 apples. How many apples and pears does he have? Can we use model drawing to solve this qn?

Hi

using model drawing...

http://i39.tinypic.com/2dbw8km.jpg\">

cheers.

[Xiao Hu]

MathIzzzFun:

Tresille:

Hi, need your assistance.


John has a total of 20 apples and pears. If he exchanges every pear for 2 apples, she will have 28 apples. How many apples and pears does he have? Can we use model drawing to solve this qn?

Hi

using model drawing...

http://i39.tinypic.com/2dbw8km.jpg\">

cheers.

There you go, another strategry to add to the repertoire. Thanks for showing this Model Drawing, MathIzzzFun. This Model Drawing is probably the most important strategry in problem solving. I'm still struggling with Model Drawing as I'm visually-chanllenged. I had failed or fared very poorly in my arts class, whatever kind of drawing or paintings.

Thanks again,
Xiaohu.

[chloecube]

jess has a bag of balloons. after giving 8 balloons to each pupil, she has 4 balloons left.if she give 5 balloons to everyone, she would have 58 balloons left. how many pupils does she have?