Q&A - P3 Math

[corneyAmber]

vmom:

Hi All,

Need help with a P3 Question with the help of model diagram

There are a total of 232 balls.
There are 12 more red balls than blue balls.
There are twice as many green balls as red balls.
How many green balls are there?

This is a solution from my dd:

G___12___12
R___12
B___
where___=u

12x 3= 36
4u -> 232-36
u -> 196/4 = 49

Green balls = 49x2 + 12x2 = 98+24= 122

[tianzhu]

mama_10:

A pen cost $1 and a eraser cost $0.2,John paid $20 for some eraser and pen. 5/8 items he bought were eraser, how many eraser he bouhght?


thks!

Hi

A quick answer.

Using “Number* Value” Method.

Pens ------ 3 units
Erasers ------ 5 units

Pens ------ 3*100 ------ 300 units
Erasers ------ 5*20 ------ 100 units

400 units ------- 2000 ($20 ------ 2000 cents)

1 unit ------- 5
\t
Erasers -------5*5 ------- 25

Best wishes

[tianzhu]

htan045:

Thank you for your prompt reply.

Hi

You're welcome.

Best wishes

[vmom]

Hi ksi

Thx for ur prompt reply

[yxl]

1) Regina and Audrey went on a tour together. Regina bought 3 times as much money as Audrey. After Regina had spent $540 and Audrey spent $60, they had equal amount of money left. How much money had each of them left?

[yxl]

Miss Lim gives some erasers to her pupils. If she gives each pupil 6 erasers, there will be 5 left. If she gives each pupil 8 erasers, she will be short of 9. How many erasers does she have?







There were 1568 pupils in the hall. After 224 girls and 1/4 of the boys left the hall, there was an equal number of boys and girls remaining in the hall How many boys were there in the hall at first?

[tianzhu]

yxl:

1) Regina and Audrey went on a tour together. Regina bought 3 times as much money as Audrey. After Regina had spent $540 and Audrey spent $60, they had equal amount of money left. How much money had each of them left?

Hi

You may use MD or Units Method to solve this question.

A quick guide to draw the MD.

Draw 3 boxes to show Regina’s money and draw 1 box to show Audrey’s money.

Cut off 540 from Regina’s boxes and 60 from Audrey’s box leaving equal portion.

From MD, note that 2 boxes ------- 480
1 box ------ 240

Amount of money each of them left ------ 240 – 60 ------ 180.

Best wishes

[tianzhu]

yxl:

Miss Lim gives some erasers to her pupils. If she gives each pupil 6 erasers, there will be 5 left. If she gives each pupil 8 erasers, she will be short of 9. How many erasers does she have?

Hi

Look at this question from another angle, if Mrs Lim gives 2 more erasers(8-6) to her pupils, she would need (5+9) or 14 more erasers.

14/2 ------ 7
There are 7 pupils.

Number of erasers ------ (7*6) + 5 ------ 47 or (7*8) – 9 ------- 47

Best wishes

[tianzhu]

yxl:

There were 1568 pupils in the hall. After 224 girls and 1/4 of the boys left the hall, there was an equal number of boys and girls remaining in the hall How many boys were there in the hall at first?

Hi

A quick guide to draw the MD.

Draw 4 boxes to show the number of boys.
1/4 of the boys left the hall
Remaining number of boys ------- 3 boxes.

Remaining number of girls ------- 3 boxes.
At first, the number of girls ------- 3 boxes + 224

Hence, 7 units + 224 ------- 1568
1 unit ------ 192

Number of boys at first ------ 4 units ------768

Best wishes

[MathIzzzFun]

yxl:

Miss Lim gives some erasers to her pupils. If she gives each pupil 6 erasers, there will be 5 left. If she gives each pupil 8 erasers, she will be short of 9. How many erasers does she have?

Hi

A solution using MD. Hope this helps.

http://www.flickr.com/photos/62167097@N02/5661546018/in/photostream/

cheers.