Q&A - P3 Math

[The Right Equation]

Honesty:

catddy2002:

[quote=\"Honesty\"]How about these questions.


1. A box with 12 sweets has a mass of 265g. The same box with 5 sweets in it has a mass of 195g. What is the mass of the empty box?

2. Mr Lim has a bag containing 9 yellow marbles and 13 green marbles. The total mass of the marbles is 136 grams. The total mass of 1 yellow and 1 green marbles is 12 grams. What is the mass of 1 yellow marble?

Hi,

I just try.
Maybe some parents might have better way to solve.

Q1. 12 sweets - 5 sweets = 7 sweets
265g - 195g = 70 g
7 sweets = 70 g
70/7 = 10g = weight of 1 sweet.
5 sweets = 10 X 5 = 50g
195g - 50g = 145 g = mass of the empty box

Q2. 1 yellow + 1 green = 12 g
9 sets = 9 x12 = 108 g
13 green marbles - 9 green marbles = 4 green marbles left
136g - 108g = 28g
28g / 4 green marbles = 7 g for each green marbles
13 green marbles = 91 g
136g - 91 g =45g
45g / 9 yellow marbles = 5 g

Yes, this is the method I used. How can we depict in models?[/quote] http://i39.tinypic.com/2s7jo8p.jpg\">

[MathIzzzFun]

Honesty:

catddy2002:

[quote=\"Honesty\"]How about these questions.


1. A box with 12 sweets has a mass of 265g. The same box with 5 sweets in it has a mass of 195g. What is the mass of the empty box?

2. Mr Lim has a bag containing 9 yellow marbles and 13 green marbles. The total mass of the marbles is 136 grams. The total mass of 1 yellow and 1 green marbles is 12 grams. What is the mass of 1 yellow marble?

Hi,

I just try.
Maybe some parents might have better way to solve.

Q1. 12 sweets - 5 sweets = 7 sweets
265g - 195g = 70 g
7 sweets = 70 g
70/7 = 10g = weight of 1 sweet.
5 sweets = 10 X 5 = 50g
195g - 50g = 145 g = mass of the empty box

Q2. 1 yellow + 1 green = 12 g
9 sets = 9 x12 = 108 g
13 green marbles - 9 green marbles = 4 green marbles left
136g - 108g = 28g
28g / 4 green marbles = 7 g for each green marbles
13 green marbles = 91 g
136g - 91 g =45g
45g / 9 yellow marbles = 5 g

Yes, this is the method I used. How can we depict in models?[/quote]Q2-

http://i40.tinypic.com/rk3jmh.png\">

cheers.

[MathIzzzFun]

happyheart:

This question, logically can be solved by making the denominator the same but DS has not been taught so. How may I best approach to teach him? Pls help.


Q) John read 2/9 of a book on Monday. He then read 1/3 of the book on Tuesday. He then completed reading the rest of the book on Wednesday. What fraction of the book did he read on Wednesday?

This question is from Rosyth SA1 2012 , Q40. This paper consists of 3-4 similar fraction questions. Thanks.

Equivalent fractions are covered in P3 syllabus. So, in this case, the student is expected to convert 1/3 to the equivalent fraction 3/9 and then work out the remaining fraction.

cheers.

[Honesty]

:thankyou:

[happyheart]

catddy2002:

happyheart:

This question, logically can be solved by making the denominator the same but DS has not been taught so. How may I best approach to teach him? Pls help.


Q) John read 2/9 of a book on Monday. He then read 1/3 of the book on Tuesday. He then completed reading the rest of the book on Wednesday. What fraction of the book did he read on Wednesday?

This question is from Rosyth SA1 2012 , Q40. This paper consists of 3-4 similar fraction questions. Thanks.

Hi,

Suggest use model.

A book = 9 units
Monday = 2 units
Tue = 1/3 of the book means = 9 units / 3= 3 units
Wed = 9-2-3= 4 units
4 units = 4/9 in fraction

Thank you. I will use the method to coach him.

[happyheart]

MathIzzzFun:

happyheart:

This question, logically can be solved by making the denominator the same but DS has not been taught so. How may I best approach to teach him? Pls help.


Q) John read 2/9 of a book on Monday. He then read 1/3 of the book on Tuesday. He then completed reading the rest of the book on Wednesday. What fraction of the book did he read on Wednesday?

This question is from Rosyth SA1 2012 , Q40. This paper consists of 3-4 similar fraction questions. Thanks.

Equivalent fractions are covered in P3 syllabus. So, in this case, the student is expected to convert 1/3 to the equivalent fraction 3/9 and then work out the remaining fraction.

cheers.

Emmm...DS school has not taught equivalent fraction this year, just a lot of whole number and heuristics. Maybe the school is saving for term 2&3.

[jolenekoh]

Hi hi



Shaun has thrice as many stickers as Jason. When Shaun gives 24 stickers to Jason, they will have the same number of stickers each. How many stickers does Shaun have than Jason at first?

Thank you

[sembgal]

jolenekoh:

Hi hi



Shaun has thrice as many stickers as Jason. When Shaun gives 24 stickers to Jason, they will have the same number of stickers each. How many stickers does Shaun have than Jason at first?

Thank you

48 stickers.

[jolenekoh]

Hi sembgal Thank you.


Can give me the step? or model?

I get the ans...but dont know how to explain...hahahah

sembgal:

jolenekoh:

Hi hi


Shaun has thrice as many stickers as Jason. When Shaun gives 24 stickers to Jason, they will have the same number of stickers each. How many stickers does Shaun have than Jason at first?

Thank you

48 stickers.

[sembgal]

jolenekoh:

Hi sembgal Thank you.


Can give me the step? or model?

I get the ans...but dont know how to explain...hahahah

sembgal:

[quote=\"jolenekoh\"]Hi hi


Shaun has thrice as many stickers as Jason. When Shaun gives 24 stickers to Jason, they will have the same number of stickers each. How many stickers does Shaun have than Jason at first?

Thank you

48 stickers.

[/quote]First u draw 3 units for Shaun and below that you draw 1 unit for Jason.
Transfer 1 unit over from Shaun's to Jason.
That makes them both equal units of 2 each.
Since 1 unit is 24, Shaun has 2 more units than Jason at first, you take 24X2=48.

You can use this explaination and guide your child to draw the model by himself/herself and explain step by step.