Tutor MathsGuru: Ask me for your burning Maths questions!

[Yerdua]

Dharma:

Yerdua:

Hi,

These are p1 qns under the \"Addition and Subtraction Within 20\" topic.
Qns 1: ___ +8-5= 10
Qns 2: ____-7+4=10

Pls advise on how should i teach my ds? Thks thks!

For this sort of qns, best to work backwards.

For Qn 1

Let’s say we Ali has a certain number of sweets at first. His mother gives him 8 sweets and then he gives 5 sweets to his sister. Ali will have 10 sweets at last.

Now working backwards, Ali would have had 15 sweets (10 + 5) i.e. 5 sweets more, before giving away 5 sweets to his sister.

Before that, Ali will be receive 8 sweets from his mum to have 15 sweets. So, before getting the 8 sweets from his mum, Ali will have 8 sweets less ( 15 – 8= 7) Ali will have 7 sweets at first.

No. of sweets at first = 10 + 5 - 8 = 7

You may wish to try Qn 2.

Thanks Dharma, this a good method of working back! I'll try with ds soon! Thks!

[ruyu]

maybe i will take a part time job here. Although i dont know some questions :oops: try my best. PSLE this year maybe doing all the questions will help

[YLH88]

Hi Maths Monster,


Thank you for the model solution !

[YLH88]

Hi,


Need help with the below question. The answer given used the guess and check method, but is it possible to do this using the Assume method ?

Class 6A has 40 pupils. Class 6B has 30 pupils. The pupils in both classes took the same test and scored an average of 90 marks. Given that the average score of Class 6B was 7 marks higher than that of Class 6A, find the average score of Class 6A.
(ans : 87)

Thank you.

[Maths Monster]

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[Maths Monster]

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[littlecloud]

Hi,

I have 2 separate maths question that I need help to solve:
(1) Tom and Jerry each has some money. If Tome spends $90 per day and Jerry spends $45 each day, Tom will have $1100 left when Jerry has spent all his money. If Tom spends $45 each day and Jerry spends $90 each day, Tom will have $1700 left when Jerry has spent all his money. How much did Jerry have?
Answer is $400, but how to get that?

(2) A, B, C and D each have some money. The amount of money A has is 1/3 of the total amount of money B, C and D have. The amount of money B has is 1/4 the amount of money A, C and D have. The amount of money C has is 1/5 the amount of money A, B and D have. If D has $1725, how much do they have altogether?

Thanks for helping.

[Maths Monster]

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[Vanilla Cake]

littlecloud:

Hi,

I have 2 separate maths question that I need help to solve:
(1) Tom and Jerry each has some money. If Tome spends $90 per day and Jerry spends $45 each day, Tom will have $1100 left when Jerry has spent all his money. If Tom spends $45 each day and Jerry spends $90 each day, Tom will have $1700 left when Jerry has spent all his money. How much did Jerry have?
Answer is $400, but how to get that?

(2) A, B, C and D each have some money. The amount of money A has is 1/3 of the total amount of money B, C and D have. The amount of money B has is 1/4 the amount of money A, C and D have. The amount of money C has is 1/5 the amount of money A, B and D have. If D has $1725, how much do they have altogether?

Thanks for helping.

Hi littlecloud,
Mathsguru had provided her solutions for your 2 questions on http://www.kiasuparents.com/kiasu/forum/viewtopic.php?t=6373&postdays=0&postorder=asc&start=780.
http://www.postimage.org/image.php?v=gxtwwpi
http://www.postimage.org/image.php?v=gxtwyUr

[Maths Monster]

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