Hi - PSLE Maths is this Friday. I want to thank everyone for your help.

:thankyou: very much for your time and effort. I appreciate what all of you have done.

tianzhu:

AJH:

[quote=\"tianzhu\"]
But isn't 30% of students in the parade ground and 70% of students at the indoor sports hall = 180 + 280 = 460?

Hi

Good Morning.

The number of boys and girls remains the same before and after the transfer. The total number of 1000 did not change at all.

The number of girls stays the same that is 480 before and after.

In this case

Number of girls in the beginning ------- 480

Number of girls in the end (after the transfer)

Parade square ------- 3 parts ------ 3*55 ------- 165 (30% of 550)

Indoor stadium -------- 7 units ------- 7*45 ------- 315 (70% of 450)

Total number ------ 165 + 315 ------- 480

Best wishes[/quote] :thankyou: for all the help you have given me.

tianzhu:

AJH:

Hi - nd help with this question:


Mr Lee packed some oranges into big boxes and apples into small boxes. Each big box contained 50 oranges and each small box contained 30 apples. After packing, there were 12 more big boxes than small boxes. Given that there were 1240 fewer apples than oranges, how many oranges were there? ( ans: 2200 )

Thank you.

Hi

You may use MD or work with units.

Draw three boxes (stacked up) to show the number of apples.

12*50 ------ 600

Draw five boxes to show the number of oranges. To make the MD look neater, divide 600/5 to give 120, add a bar showing 120 to each of the box.

5 boxes + 600 ------- 3 boxes + 1240

2 boxes ------- 640

1box ------ 320

Number of apples ------- 2200

Best wishes

:thankyou: I understand now.

tianzhu:

AJH:

Hi - how did u get 480? I got 460. Thank u.

Hi

This question is crafted in such a way that it’s neat to use MD.

You may also use Units and Parts or letters of the alphabet to show the variables.

What you are seeing now is already the MD.The boxes are labelled with units and parts to enable students using the UP to see better.

The number “480” refers to the number of girls.

Best wishes

:thankyou: for your help. But isn't 30% of students in the parade ground and 70% of students at the indoor sports hall = 180 + 280 = 460?

Hi - nd help with this question:


Mr Lee packed some oranges into big boxes and apples into small boxes. Each big box contained 50 oranges and each small box contained 30 apples. After packing, there were 12 more big boxes than small boxes. Given that there were 1240 fewer apples than oranges, how many oranges were there? ( ans: 2200 )

Thank you.

tianzhu:

htn:

tianzhu
how to use MD to solve this q? can teach me?
TIA

Hi mumwgals and htn

MD refers to “Model Drawing” or Model Diagram”.

In this question, the units or boxes showing boys and girls in the parade ground and indoor hall are of different measures. They are not of the same sizes.

A student should note that the number of boys and girls remains the same before and after the transfer. The total number of 1000 did not change at all.

There are two unknowns with two linear equations.Recall the time at lower primary when you’re using the stars and moons, you could actually solve the equations pictorially as shown in the slide. This question is crafted in such a way that it is pretty neat to use MD.

Otherwise, students may choose to work using “Units and Parts” or letters of the alphabet as representation. Use the method you are comfortable with.

Hope this helps.

Best wishes

http://farm7.static.flickr.com/6070/6154555481_a1f43e1359_z.jpg\">

Hi - how did u get 480? I got 460. Thank u.

Hi. I nd help with this ques.


Brendan and Raidah saved $6475.60 altogether. 2/5 of Brendan’s savings was $341.50 more than 1/5 of Raidah’s savings. How much more money than Brendan did Raidah save?

Can’t seem to get the ans - $1020.20. Thank you.

tianzhu:

Hi


Hope this helps.

Best wishes

http://farm8.staticflickr.com/7246/7459644570_6087607dbd_z.jpg\">

:thankyou: very much.

MathIzzzFun:

AJH:

Hi -


Q. Jane and May share a box of beads. If Jane were to give 25% of her share to May, Jane would have half of May's final share. If Jane were to give 16 beads to May, Jane would have 54 fewer beads than May. If they were to pack all their beads into boxes of 25 each, what is the least number of boxes required to pack all of them?

Thank you.

Hi

You can see the solution quite easily with MD... I will use units to save time.

If Jane were to give 16 beads to May, Jane would have 54 beads fewer than May
After:
Jane --> 4 units
May --> 4 units + 54
At first:
Jane -->4 units + 16
May --> 4 units + 38

If Jane were to give 25% of her share to May, Jane would have half of May's final share.
1/4 of Jane's share --> 1 unit + 4
After:
Jane --> 3 units + 12
May --> 5 units + 42 = 2 x (3 units+12)
5 units + 42 = 6 units + 24
1 unit --> 18

Number of beads each had:
Jane --> 4 x 18 + 16 = 88
May --> 4 x 18 + 38 = 110
..I believe you can carry on from here..

cheers.

:thankyou: If u hv the time can u show me the MD.

Hi -


Q. Jane and May share a box of beads. If Jane were to give 25% of her share to May, Jane would have half of May’s final share. If Jane were to give 16 beads to May, Jane would have 54 fewer beads than May. If they were to pack all their beads into boxes of 25 each, what is the least number of boxes required to pack all of them?

Thank you.