Q&A - P3 Math

[HAPPYH]

bluesclue:

CMF:

[quote=\"bluesclue\"] Mass of a glass of water =400g. After emptying half the water, the mass =240g.


Question: what is the mass of the empty glass?

If after emptying half the water, the mass (of the remaining half water + glass) = 240g

Then it means half of the water emptied = 160g (400g - 240g)

Therefore full glass of water (without the glass) : 160g x 2 = 320g

The empty glass itself would be : 400g - 320g = 80g

CMF,
Thanks for your post. The model answer given is 40g. Any thoughts why?[/quote]Hi
I am not sure you (or the teacher) modified this question. There is a similar question in P3 My pals workbook but the numbers are different.

Mass of a glass of water =200g. After emptying half the water, the mass =120g.
If you use these numbers the answer will be 40 g (mass of empty glass). Somehow your question has the double of these numbers so the mass of empty glass should be 80g (everything doubled).

Hope this helps!

[bluesclue]

Hi, Yes, numbers were changed as you have noticed. with 200g/ 120g for full/half glass , DS's answer for the empty glass was 40g, but teacher marked it as wrong and said answer should be 20g. :? So just wanted to find out if our understanding is correct. With CMF and your confirmation, i think 40g should be the right answer, thanks.

[HAPPYH]

Hi, I just checked my DD’s workbook. Her teacher marked 40g as the correct answer.

[bluesclue]

Hi HappyH,

Thanks for checking back and confirm.

[HAPPYH]

bluesclue:

Hi HappyH,
Thanks for checking back and confirm.

You are welcome.

[vividlaurel]

Hi,


Can anyone help with this problem. The answer should be got using Heuristics.

Johnny had 30 ml more orange juice than Chloe at first. After Johnny drank 180 ml of orange juice, Chloe had twice as much orange juice as Johnny. How much orange juice did Johnny have at first?

TIA

[HAPPYH]

vividlaurel:

Hi,


Can anyone help with this problem. The answer should be got using Heuristics.

Johnny had 30 ml more orange juice than Chloe at first. After Johnny drank 180 ml of orange juice, Chloe had twice as much orange juice as Johnny. How much orange juice did Johnny have at first?

TIA

Is the answer 330?

180-30=150
150+150+30=330

Is this answer correct?

[vividlaurel]

Thanks HappyH,


Yes, that is the correct answer. I finally figured it out after posting it here.

HAPPYH:

vividlaurel:

Hi,

Can anyone help with this problem. The answer should be got using Heuristics.

Johnny had 30 ml more orange juice than Chloe at first. After Johnny drank 180 ml of orange juice, Chloe had twice as much orange juice as Johnny. How much orange juice did Johnny have at first?

TIA

Is the answer 330?

180-30=150
150+150+30=330

Is this answer correct?

[HAPPYH]

vividlaurel:

Thanks HappyH,


Yes, that is the correct answer. I finally figured it out after posting it here.

HAPPYH:

[quote=\"vividlaurel\"]Hi,

Can anyone help with this problem. The answer should be got using Heuristics.

Johnny had 30 ml more orange juice than Chloe at first. After Johnny drank 180 ml of orange juice, Chloe had twice as much orange juice as Johnny. How much orange juice did Johnny have at first?

TIA

Is the answer 330?

180-30=150
150+150+30=330

Is this answer correct?

[/quote]Yeh, finally got something correct

[vividlaurel]

LOL! I know the feeling! Was so happy when I got the answer. Isn’t it weird when P3 Maths is beyond you…