Q&A - P3 Math

[tianzhu]

peggy:

Thanks again, Tianzhu and Starlight.


Have a great weekend !

Hi

You're welcome.

Best wishes

[small]

peggy:

Need help again for this P4 qtn. Saw from last year's posting but could not understand the workings without models.


Matthew and Paul have a sum of money at first. If Matthew gives Paul $80, he will have twice as much as Paul. If Matthew gives Paul $20, he will have thrice as much as Paul. How much money did Matthew have at first?

Thanks!

Hi Peggy,

Hope this helps. My model is not as good as Tianzhu master.

http://s2.postimage.org/1j0jr-a34963.jpg\">

Matthew had $560 at first.


.

[tianzhu]

Hi peggy


Hope this helps.

Best wishes.

http://farm2.static.flickr.com/1389/5112750348_b9f86799b4_b.jpg\">

[peggy]

Thanks, Small & Tianzhu !


Have a good day !

[tianzhu]

peggy:

Thanks, Small & Tianzhu !


Have a good day !

Hi

You're welcome.

Best wishes

[Smosh]

Hi guys!


Anne has $165 and Cally had $200 at first.
After spending an equal amount of money, Cally had twice as much money as Anne. How much money did each of them spend?

I was able to solve it by algebra, but my son in P4 cant use it.
Anyone able to help me with the correct method of solving?

Thanks so much in advance

[Dharma]

Smosh:

Hi guys!


Anne has $165 and Cally had $200 at first.
After spending an equal amount of money, Cally had twice as much money as Anne. How much money did each of them spend?

I was able to solve it by algebra, but my son in P4 cant use it.
Anyone able to help me with the correct method of solving?

Thanks so much in advance

Since Anne and Cally spent the same amt of money each, the difference in the amount of money they are left with does not change (ie $200 - $165 = $35)

2u - 1u = 1u = $35
Amt of money each of them spent = $165 - $35 = $130 or $200 - $70 = $130

[Modelmatics]

Smosh:

Hi guys!


Anne has $165 and Cally had $200 at first.
After spending an equal amount of money, Cally had twice as much money as Anne. How much money did each of them spend?

I was able to solve it by algebra, but my son in P4 cant use it.
Anyone able to help me with the correct method of solving?

Thanks so much in advance

This question involves the <a href=\"http://www.teach-kids-math-by-model-method.com/constant-difference-concept.html%22%3EConstant Difference Concept</a> as well as the Working Backwards Heuristics.

Step 1: It is easier to work backwards by drawing the \"After\" model first. Since Cally had twice as much money as Anne in the end, we draw 2 boxes to represent Cally's money and 1 box to represent Anne's money. We leave a big gap on the left of the model to add in the \"Spent\" part later. (This aids visualisation)

http://postimage.org/image/m6rlodj8/

Step 2: Since both of them spent an equal amount of money, we draw 1 box each (of equal size) to the left of both of their models to represent the same amount of money spent.

http://postimage.org/image/m8qpsaro/

Step 3: As Anne has $165 and Cally had $200 at first, we put these 2 values into the model.

http://postimage.org/image/m93y32pw/

From the model,

1 unit ----------> $200 - $165 = $35

From Anne's model,

Amount spent = $165 - $35 = $130

Therefore, they spent $130 each.

[doraemo]

hi ,


Anyone able to help me with the correct method of solving:

Richard and Andrew had the same amount of money each.

When Richard spent $147, Andrew had 4 times as much money as what Richard had left.

How much did Richard have at first?


Thanks so much in advance .

[jedamum]

doraemo:

hi ,


Anyone able to help me with the correct method of solving:

Richard and Andrew had the same amount of money each.

When Richard spent $147, Andrew had 4 times as much money as what Richard had left.

How much did Richard have at first?


Thanks so much in advance .

can use model.
At first:
R[][][][]
A[][][][]

After spending $147
R[]
A[][][][]

ie 3U = 147
1U = 147 / 3 = 49
At first, Richard has as much as Andrew ie 4U ie 4 x 49 = $196
or Richard at first = $49+$147=$196

This is my first attempt in this thread.