Q&A - P4 Math

[snowball]

MathIzzzFun:

snowball:

pr 4 - Fraction


1) Esther had $350 more than Kevin. Ester spent 3/4 of her money & Kevin spent 4/7 of his money. In the end, Kevin & Esther had the same amout of money left. Find the amout of money Kevin had at first.

2)At the graduation ceremony, there were 30 less boys than girls.After 3/5 of the boys & 5/8 of the girls had left the hall for recess, there was an equal number of boys & girls that remained behind. Find the number of boys who were presented at the graduation ceremony at first.

TIA

equal fraction method :

1)
Esther's money left = Kevin's money left
1/4 of Esther's money = 3/7 Kevin's money
3/12 of Esther's money = 3/7 of Kevin's moneyEsther's money at first --> 12 units
Kevin's money at first --> 7 units
Esther had $350 more than Kevin, so
5 units --> $ 350
1 unit --> $70
Kevin's money at first --> $490


2)
Number of boys remaining in hall = Number of girls remaining in hall
2/5 of total number of boys = 3/8 of total number of girls
6/15 of total number of boys = 6/16 of totla number of girlsTotal number of boys --> 15 units
Total number of girls --> 16 units
There were 30 less boys than girls
1 unit --> 30
Total number of boys --> 450

cheers.

Dear MathIzzzFun, please explain ( how to explain to the kids) why we need to change to same numerator TIA

[MathIzzzFun]

snowball:

MathIzzzFun:

[quote=\"snowball\"]pr 4 - Fraction


1) Esther had $350 more than Kevin. Ester spent 3/4 of her money & Kevin spent 4/7 of his money. In the end, Kevin & Esther had the same amout of money left. Find the amout of money Kevin had at first.

2)At the graduation ceremony, there were 30 less boys than girls.After 3/5 of the boys & 5/8 of the girls had left the hall for recess, there was an equal number of boys & girls that remained behind. Find the number of boys who were presented at the graduation ceremony at first.

TIA

equal fraction method :

1)
Esther's money left = Kevin's money left
1/4 of Esther's money = 3/7 Kevin's money
3/12 of Esther's money = 3/7 of Kevin's moneyEsther's money at first --> 12 units
Kevin's money at first --> 7 units
Esther had $350 more than Kevin, so
5 units --> $ 350
1 unit --> $70
Kevin's money at first --> $490


2)
Number of boys remaining in hall = Number of girls remaining in hall
2/5 of total number of boys = 3/8 of total number of girls
6/15 of total number of boys = 6/16 of totla number of girlsTotal number of boys --> 15 units
Total number of girls --> 16 units
There were 30 less boys than girls
1 unit --> 30
Total number of boys --> 450

cheers.

Dear MathIzzzFun, please explain ( how to explain to the kids) why we need to change to same numerator TIA[/quote]so that we will get this model :

http://i48.tinypic.com/6plyj6.png\">

cheers.

[snowball]

MathIzzzFun:

[Dear MathIzzzFun, please explain ( how to explain to the kids) why we need to change to same numerator TIA

so that we will get this model :

http://i48.tinypic.com/6plyj6.png\">

cheers.[/quote]
Dear MathIzzzFun, :thankyou: :please:

[AgonyMum]

Please help to solve these 2 questions using both model and equation methods.P4 standard

Thanks very much.

1. Fiona had 3 times as many stickers as dolls. After she gave away 7 stickers and 10 dolls, the number of stickers was 4 times the number of dolls. How many stickers and dolls did she have at first?

2.There were 5 times as many candies as sweets in a store. After 16 candies were sold and 16 sweets were brought into the store, the number of candies was 3 times the number of sweets. If each item cost 80 cents, how much money would be collected from the sale of the sweets?

[BigDevil]

http://i47.tinypic.com/2ez5qit.jpg\">

[dazzlego]

AgonyMum:

Please help to solve these 2 questions using both model and equation methods.P4 standard

Thanks very much.

1. Fiona had 3 times as many stickers as dolls. After she gave away 7 stickers and 10 dolls, the number of stickers was 4 times the number of dolls. How many stickers and dolls did she have at first?

2.There were 5 times as many candies as sweets in a store. After 16 candies were sold and 16 sweets were brought into the store, the number of candies was 3 times the number of sweets. If each item cost 80 cents, how much money would be collected from the sale of the sweets?

Hi AgonyMum,

The total at first and in the end must be the same
At first,
Candies = 5 units, Sweets = 1 unit (Total = 6 units)
Candies = 10 units, Sweets = 2 units (Total = 12 units)
In the end,
Candies = 3 units, Sweets = 1 unit (Total = 4 units)
Candies = 9 units, Sweets = 3 units (Total = 12 units)

1 unit -> 16
12 units ->192
192 x $0.80 = $153.60

Hope it is correct. I am sorry if it is not clear or incorrect. I am doing it in rush
Draw the model just in case you need to see the model

http://i46.tinypic.com/2010zgk.jpg\">

Cheers :celebrate:

[MathIzzzFun]

AgonyMum:

Please help to solve these 2 questions using both model and equation methods.P4 standard

Thanks very much.

1. Fiona had 3 times as many stickers as dolls. After she gave away 7 stickers and 10 dolls, the number of stickers was 4 times the number of dolls. How many stickers and dolls did she have at first?

2.There were 5 times as many candies as sweets in a store. After 16 candies were sold and 16 sweets were brought into the store, the number of candies was 3 times the number of sweets. If each item cost 80 cents, how much money would be collected from the sale of the sweets?

Q2.

http://i47.tinypic.com/zv3jpf.png\">

cheers.

[AgonyMum]

Thank you all so much for helping I am still trying to figure out the solutions.....lost right now.

Possible to solve using equation/ substitution/ algebra?
Thanks!

[BigDevil]

AgonyMum:

Thank you all so much for helping I am still trying to figure out the solutions.....lost right now.

Possible to solve using equation/ substitution/ algebra?
Thanks!

Fiona had 3 times as many stickers as dolls. S = 3D

After she gave away 7 stickers and 10 dolls, the number of stickers was 4 times the number of dolls.
S-7 = 4(D-10)

How many stickers and dolls did she have at first?
Substituting S,

3D - 7 = 4D - 40
D = 33
S = 33 x 3 = 99

[cimman]

AgonyMum:

Thank you all so much for helping I am still trying to figure out the solutions.....lost right now.

Possible to solve using equation/ substitution/ algebra?
Thanks!

hi AgonyMum,
have a look at this technique: http://www.kiasuparents.com/kiasu/forum/viewtopic.php?f=67&t=25121&start=1260

you can use the exact same technique for your problems.
First draw the table, then transfer all the values over to the table.

let me know if you need help in this area.