Q&A - P5 Math
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tianzhu:
Tianzhu, thank u. Will ask my boy to try the qn wh u gave with G&C.
Himemouse:
Check that answer for 1st and 2nd must be the same, hence the answer is 8. Is this method feasible and ok to use. Thank u
Yes, you may use GC, but it is less efficient at upper primary level as the numbers are bigger.
Let your boy try to use GC for this question.
Mr Chia gives some erasers to his students. If he gives 7 erasers to each student, he will have 53 erasers left. If he gives 9 erasers to each student, he will have 5 erasers left.
(a) How many students does he have?
(b) Find the number of erasers he has at first.
Usually under examination environment, students are hard pressed to finish the questions within tight schedule and a more efficient method would be more advisable.
Best wishes -
Joanne paid a total of $52 for 2 similar blows and 2 similar plates
five bowls cost as much as three plates
how much money would joanne save if she bought two bowls and 2 plates -
carol73:
HiJoanne paid a total of $52 for 2 similar blows and 2 similar platesfive bowls cost as much as three plates
how much money would joanne save if she bought two bowls and 2 plates
Please check with your source.
A similar question was discussed in the P4 thread.
Hope this helps.
Best wishes![](\"http://farm9.staticflickr.com/8086/8551140688_ab09f44b7a_z.jpg\")
http://farm9.staticflickr.com/8086/8551140688_ab09f44b7a_z.jpg\">
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Need some help. TIA!
1. 5/8 of Ann’s stamps is equal to 2/5 of Tony’s stamps. If Tony gives 18 stamps to Ann, they will then have the same number of stamps. How many stamps do they have altogether?
2. Mary spent $270 on a necklace. She spent 1/7 of her money on a dress. She then had 3/8 of her money left. How much money did she have at first?
3. Yesterday, Ron had 72 more stamps than Lisa. Today, Ron gave Lisa 2/5 of his stamps. As a result, he has 1/2 as many stamps as Lisa now. How many stamps did Ron have yesterday? -
let me try…
1. Ann - 16u
Tony - 25u
total 16+25=41u
41/2=20.5
25-20.5=4.5u
4.5u - 18 stamps
1u - 4 stamps
4x41 =164 -
![](\"http://i50.tinypic.com/5l6g7k.jpg\")
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![](\"http://i49.tinypic.com/2zinaco.jpg\")
Pl help :? -
Jamesbond:
Pl help :?
Shaded part is 5/8 of the square.
Therefore answer is 240 x (5/8) = 150 cm square.
Explanation:
We know that AP = PB and AQ = QD.
Therefore, it is clear that the square can be divided into 4 equal small squares, which can then be cut up into 8 small triangles.
It should be obvious from the drawing that half of APXQ is shaded where X is the center point of the square.
Also, it should be obvious that the other 2 shaded triangles FBC and QDC can be pieced together to form a rectangle that is half of the entire square.
Therefore, out of the 8 small triangles, we have 6 shaded triangles. -
[quote]2. Mary spent $270 on a necklace. She spent 1/7 of her money on a dress. She then had 3/8 of her money left. How much money did she have at first?[/quote]
It might be good to draw the model for this question (if you have trouble visualizing) although I am not going to provide one in the following solution.
After spending $270, Mary has some money left. Let us call that the remainder.
She then spent 1/7 of the remainder on a dress.
Thereafter, she is left with 6/7 of the remainder.
Therefore, 6/7 of remainder = 3/8 of her total money
For reasonable comparison, you need the unit size to be the same!
As such, find the lowest common multiple of 6 and 3. Then make the numerator the same (same amount represented by the same number of units -> units are of the same size), i.e.
6/7 of remainder = 6/16 of her total money
As such, her total money can be represented using 16 units. The remainder is then represented using 7 units.
The money spent on the necklace is hence represented by
16 - 7 = 9 units
9 units = $270
1 unit = $270 / 9 = $30
16 units = $30 x 16 = $480 -
ChewingPencilLine:
[quote]2. Mary spent $270 on a necklace. She spent 1/7 of her money on a dress. She then had 3/8 of her money left. How much money did she have at first?
It might be good to draw the model for this question (if you have trouble visualizing) although I am not going to provide one in the following solution.
After spending $270, Mary has some money left. Let us call that the remainder.
She then spent 1/7 of the remainder on a dress.
Thereafter, she is left with 6/7 of the remainder.
Therefore, 6/7 of remainder = 3/8 of her total money
For reasonable comparison, you need the unit size to be the same!
As such, find the lowest common multiple of 6 and 3. Then make the numerator the same (same amount represented by the same number of units -> units are of the same size), i.e.
6/7 of remainder = 6/16 of her total money
As such, her total money can be represented using 16 units. The remainder is then represented using 7 units.
The money spent on the necklace is hence represented by
16 - 7 = 9 units
9 units = $270
1 unit = $270 / 9 = $30
16 units = $30 x 16 = $480[/quote]Hi, Sorry to interrupt..She only spent 1/7 of the money on the dress and not the remainder. So the steps are
1/7=8/56
3/8=21/56
21/56+8/56=29/56
56-29=27
270/27=10
56*10=560
Correct me if I am wrong.
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