Q&A - P2 Math

[forestcadee]

Hi, all, thanks for the help. Had requested my dd to ask teacher for further detail if this type of question be out in the test/practice.

[Michaelia0816]

You’ re welcome!

[xian_kai]

Hi


Appreciate some pointers to this Maths question:

http://i45.tinypic.com/keyzhc.jpg\">

Thanks much

(Maths maths maths made me mad )

[ammonite]

Hi, I think this is a tough question for P2, even some P3 can get confused, but can be solved using model method. The answer is 3462.


I don’t know how to upload image, but here is a rough idea. Maybe someone can upload a clearer example later.

1. Treat each number as an identity for drawing the bar. (eg (Th, H, T, O)
2. Tens and Thousands are the easiest since we already know that Th is 3. Therefore T is 6. Draw the model for these two.
3. Hundreds and Ones are harder to untease, but if you read carefully, the difference between the bar for H and T, will equal the size for O, and H is also equals to 2 Os.
4. Therefore 3 Os is equal to T (which you already know is 6), shading two units equal to H (therefore 4). Hence O is 2.

Arrange the numbers back in order you get 3462. To double check, add them up and you get 15.

[xian_kai]

Hi ammonite


Thanks much for the solution. Didn’t cross my mind to use models and solve this.

I also find that this question is too tough for lower primary. Wonder why it was printed in DS1 P2 Maths assessment book?

[ammonite]

Most welcomed! Don't worry, my hub took one look, winced and refused to even try it - like an overgrown P2 kid, heh. But after a while the sums will all start to look the same and you will recognize their 'disguises'.

[nonKiasu]

xian_kai:

Hi


Appreciate some pointers to this Maths question:

http://i45.tinypic.com/keyzhc.jpg\">

Thanks much

(Maths maths maths made me mad )

Hi. I attempt to solve this. I would say it's difficult for a P2 without adult's help. If it's my DS's problem, I will need to solve it first, then I tell him to use the sequence of the clue as follow:

(Clue 5)
(Clue 3)
(Clue 1)
(Clue 4)

(Clue 5) will give 3 H T O
(Clue 3) will give T = 3x2=6
(Clue 1) will give H+O = 15-3-6=6

From (Clue 1) + (Clue 4), use the method that taught to my DS (hopefully he still remember how to do):

(Clue 1), (Clue 4)
0+6=6, 6/0 (not yet learn, DS will say cannot)
1+5=6, 5/1 = 5 (wrong)
2+4=6, 4/2 = 2 (YES!)
So, H = 4, O = 2

ans: 3462

Leaving my DS alone to solve it, I am sure he can't do it.
I hate this kind of question bec P2 can't deduce the sequence of the clues and don't know where to start.

[Lexmark]

Please help:

Write the greatest 2-digits number such that the sum of the two digits is 10.
TQ!

[Sun_2010]

Lexmark:

Please help:

Write the greatest 2-digits number such that the sum of the two digits is 10.
TQ!

91 ?

[Lexmark]

TQ.

Teacher marked as wrong, now I’m not sure…
1. Write the greatest 2-digit number such that the sum of the two digits is 10. (not 91?)
2. Write the greatest 3-digit number such that the sum of the three digits is 20.(not 992?)
3. Write the smallest 3-digit number such that the sum of the three digits is 15.(not 159?)