P2 Math - General Discussion

[rocklee]

How many ones are there in 857? Should it be 857 or 7? Anyone care to enlighten me?


Thanks

[corneyAmber]

rocklee:

How many ones are there in 857? Should it be 857 or 7? Anyone care to enlighten me?


Thanks

If this is testing the identification of where ones are found, should be 7, otherwise this question has no meaning......because everything can be represented in the base unit of ones in denary form, even 1,000,000.

And if this is P1 question, they only learn numbers from 1-100, only P2 learn 1-1000

[rocklee]

thanks ksi.


How many tens are there in 750. Is the ans 75 or 5?
If the ans is 75 , on this basis, should the ans be 857 in my earlier question?
FYI, this is a p2 question.

Thanks

[corneyAmber]

rocklee:

thanks ksi.


How many tens are there in 750. Is the ans 75 or 5?
If the ans is 75 , on this basis, should the ans be 857 in my earlier question?
FYI, this is a p2 question.

Thanks

We have discussed this before here:

http://www.kiasuparents.com/kiasu/forum/viewtopic.php?t=423&postdays=0&postorder=asc&start=230

[cookie]

this is from a P1 assessment book. although the answer is given, but i dont know how to teach my DS how to do the workings/solve it. anyone can advise? tks.


A + A + A + B = 40

A + A + B = 28

what is A and what is B?

[verykiasu2010]

cookie:

this is from a P1 assessment book. although the answer is given, but i dont know how to teach my DS how to do the workings/solve it. anyone can advise? tks.


A + A + A + B = 40

A + A + B = 28

what is A and what is B?

40 - 28 = 12

3A - 2A = A

B - B = zero

hence A = 12

3 A = 36

Hence B = 4

[caroline3sg]

Trial & Error method.


At first, try 10 for A, 8 for B. It doesn’t meet A + A + A + B = 40 (answer only 38, so must increase value of A and decrease value of B).

Then try 12 for A, 4 for B. You can get total 40.

[corneyAmber]

cookie:

this is from a P1 assessment book. although the answer is given, but i dont know how to teach my DS how to do the workings/solve it. anyone can advise? tks.


A + A + A + B = 40

A + A + B = 28

what is A and what is B?

A + (A + A+ + B) = 40
A + 28 = 40
A = 40 -28 = 12
B = 28 - 12 - 12 = 4

This is the \"see the pattern\" method.

[cookie]

caroline3sg:

Trial & Error method.


At first, try 10 for A, 8 for B. It doesn't meet A + A + A + B = 40 (answer only 38, so must increase value of A and decrease value of B).

Then try 12 for A, 4 for B. You can get total 40.

did the trial & error method, just that not sure is this the way to teach P1. thanks !

[cookie]

verykiasu2010:

cookie:

this is from a P1 assessment book. although the answer is given, but i dont know how to teach my DS how to do the workings/solve it. anyone can advise? tks.


A + A + A + B = 40

A + A + B = 28

what is A and what is B?

40 - 28 = 12

3A - 2A = A

B - B = zero

hence A = 12

3 A = 36

Hence B = 4

thanks!

after reading your post, it suddenly occur to me that the diff between the two sentences is an A.

so if 40 - 28 = A, then A is 12.

28 - 12 - 12 = 4 (B is 4)

to confirm, 12 + 12 + 12 + 4 = 40

this way can?