Q&A - P3 Math

[peapot]

If three items then need to use guess and check. This was what I was told by the school teacher.

[corneyAmber]

HAPPYH:

Michaelia0816:

Not possible, to use three, but after comparing two and found one of it, use it for another to compare.

Could you please help me solve the following problem using the above method? Thank you in advance.

Si Rong had 8 50 cent-coins, 20 cent coins and 10 cent coins that add upto $2. How many 50 cent coins does she have?

Peapot is right, this question can be easily solved by guess and check.

Do a table and start with
50 cts x 1 = $0.50
20 cts x 6 = $1.20
10 cts x 1 = $0.10
8 coins but $1.80, short of $0.20

50cts x 2 = $1
20cts x 4 = $0.80
10cts x 2 = $0.20
so 8 coins and $2 and he has 2 50 cts coins

[HAPPYH]

ksi:

HAPPYH:

[quote=\"Michaelia0816\"]Not possible, to use three, but after comparing two and found one of it, use it for another to compare.

Could you please help me solve the following problem using the above method? Thank you in advance.

Si Rong had 8 50 cent-coins, 20 cent coins and 10 cent coins that add upto $2. How many 50 cent coins does she have?

Peapot is right, this question can be easily solved by guess and check.

Do a table and start with
50 cts x 1 = $0.50
20 cts x 6 = $1.20
10 cts x 1 = $0.10
8 coins but $1.80, short of $0.20

50cts x 2 = $1
20cts x 4 = $0.80
10cts x 2 = $0.20
so 8 coins and $2 and he has 2 50 cts coins[/quote]Thank you KSI. Just curious to know whether any formula can be applied for this.

[HAPPYH]

peapot:

If three items then need to use guess and check. This was what I was told by the school teacher.

Thank you peapot. I am bit worried because if the numbers get bigger, then my DD will have a problem with guess and check. Or she will take very long to derive the answer.

[allcc6]

For Section C (problem sum), even if the final answer is wrong, the teacher will allocate ‘Method marks’ for number sentence/workings.


Does this ‘Method Mark’ apply for Section B?

[HAPPYH]

allcc6:

For Section C (problem sum), even if the final answer is wrong, the teacher will allocate 'Method marks' for number sentence/workings.


Does this 'Method Mark' apply for Section B?

If the question involves two or three steps and the last step is wrong, they may give 1 mark. My DD got 1 mark like that in the practice paper (corrected by form teacher), but in SA1 (not corrected by form teacher, was corrected by another teacher), it was crossed as wrong and no marks were given. I guess it depends on the teacher.

[chowon]

allcc6:

For Section C (problem sum), even if the final answer is wrong, the teacher will allocate 'Method marks' for number sentence/workings.


Does this 'Method Mark' apply for Section B?

No it doesn't.

[shurley197323]

chowon:

allcc6:

For Section C (problem sum), even if the final answer is wrong, the teacher will allocate 'Method marks' for number sentence/workings.


Does this 'Method Mark' apply for Section B?

No it doesn't.

As for my DS school. They give \"method marks\" for Section B. He got the working correct but answer wrong, so was given 1 mark.

[Monster Mummy]

Yes, for my child also the same. He did not complete the step but he is allocate 1 mark for section B. That’s why child must learn to show working although it may be mark by different teacher but who know whether any chance to get addition mark even answer is wrong.

[HAPPYH]

Monster Mummy:

Yes, for my child also the same. He did not complete the step but he is allocate 1 mark for section B. That's why child must learn to show working although it may be mark by different teacher but who know whether any chance to get addition mark even answer is wrong.

Agree with you. I always remind my DD to show working in Section B and C