2022 PSLE Discussions & Strategies (born in 2010)
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floppy\" post_id=\"2044907\" time=\"1636035008\" user_id=\"97579:
Wow thank you, nice..algebra will be more prone to mistakes for some kids? think there is a reason to teach kids on model mtd..interesting.
Let x be the number coins.Veyron\" post_id=\"2044897\" time=\"1636032263\" user_id=\"30663:
Parents need to be mindful when trying to introduce algebra to P6es because the algebra they are taught in school are very basic and they are not equipped to solve challenging math problems using algebra.
Those who swear by the algebra being the gold standard, can you demonstrate how to solve this PSLE question
Helen and Ivan had the same number of coins. Helen had a number of 50-cent coins and 64 20-cent coins. Helen's coins had a total mass of 1.134kg. Ivan had a number of 50-cent coins and 104 20-cent coins.
(a) Who has more money in coins and by how much?
(b) Given that each 50-cent coin is 2.7g more heavier than a 20-cent coin, what is the mass of Ivan's coins in kilograms?\"
Helen has
[(x-64)*0.5 + 64*0.2]
= 0.5x - 32 + 12.8
= $(0.5x -19.2) in coins... (1)
Ivan has
[(x-104)*0.5 + 104*0.2]
= 0.5x - 52 + 20.8
= $(0.5x - 31.2) in coins... (2)
Comparing (1) and (2), Helen has more money in coins.
She has [(0.5x -19.2) - (0.5x -31.2)]
= 0.5x - 19.2 - 0.5x + 31.2
= $12 more in coins.
By the way, the last part has nothing to do with algebra.
Given that Helen and Ivan has the same number of coins (x), Helen must have 40 more 50 cents coins than Ivan (104 - 64).
Therefore, Ivan coins would weight [1.134 - (40 x 2.7)]
= 1.134 - 0.108
= 1.026 kg
Thank you. You are welcome. -
Floppy, do you think there are chances that the x cant be zerolised?
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:goodpost:
AHsDad\" post_id=\"2044776\" time=\"1635985096\" user_id=\"172457:
1) Look back to the news. ST articles are on parents’ reactions, a forum writer and finally the SEAB reply to forum writer. All except the SEAB reply are opinions
2) whether 2021 maths was easier or harder is subjective. There are tutors interviewed who say roughly same standard. Some kids say harder while some, like my daughter and most her school peers, felt it similar to the psle papers of the previous years. Heard from grapevine that some exam markers deemed it slightly harder though 🤷🏽
️
3) Algebra has always been allowed. As long as kid can display understanding in the workings = accepted. Models working is more widespread and gives an added perpective to kids’ learning. Although I train my daughter in Algebra, she prefers models which is more systematic to her. It’s a good thing
4) for several years now, there was always 1-2 Olympiad style questions in psle. Would encourage future psle takers to try out Olympiad books cos there are some useful techniques. don’t force lah cos u won’t be left behind if don’t do Olympiad questions, but just that it may prove helpful. -
MrsKiasu\" post_id=\"2044908\" time=\"1636035400\" user_id=\"43981:
Wow thank you, nice..algebra will be more prone to mistakes for some kids? think there is a reason to teach kids on model mtd..interesting.[/quote]No. I don’t think one will be more prone to mistakes in one method or another if they are equally well versed in both. The problem with algebra is having a statement that includes a variable like Helen has $(0.5x -19.2). I think some kids will have some discomfort not having a “whole number” or stating the variable as part of an answer.
Let x be the number coins.floppy\" post_id=\"2044907\" time=\"1636035008\" user_id=\"97579:
[quote=Veyron post_id=2044897 time=1636032263 user_id=30663]Parents need to be mindful when trying to introduce algebra to P6es because the algebra they are taught in school are very basic and they are not equipped to solve challenging math problems using algebra.
Those who swear by the algebra being the gold standard, can you demonstrate how to solve this PSLE question
Helen and Ivan had the same number of coins. Helen had a number of 50-cent coins and 64 20-cent coins. Helen's coins had a total mass of 1.134kg. Ivan had a number of 50-cent coins and 104 20-cent coins.
(a) Who has more money in coins and by how much?
(b) Given that each 50-cent coin is 2.7g more heavier than a 20-cent coin, what is the mass of Ivan's coins in kilograms?\"
Helen has
[(x-64)*0.5 + 64*0.2]
= 0.5x - 32 + 12.8
= $(0.5x -19.2) in coins... (1)
Ivan has
[(x-104)*0.5 + 104*0.2]
= 0.5x - 52 + 20.8
= $(0.5x - 31.2) in coins... (2)
Comparing (1) and (2), Helen has more money in coins.
She has [(0.5x -19.2) - (0.5x -31.2)]
= 0.5x - 19.2 - 0.5x + 31.2
= $12 more in coins.
By the way, the last part has nothing to do with algebra.
Given that Helen and Ivan has the same number of coins (x), Helen must have 40 more 50 cents coins than Ivan (104 - 64).
Therefore, Ivan coins would weight [1.134 - (40 x 2.7)]
= 1.134 - 0.108
= 1.026 kg
Thank you. You are welcome. -
floppy\" post_id=\"2044911\" time=\"1636035906\" user_id=\"97579:
No. I don’t think one will be more prone to mistakes in one method or another if they are equally well versed in both. The problem with algebra is having a statement that includes a variable like Helen has $(0.5x -19.2). I think some kids will have some discomfort not having a “whole number” or stating the variable as part of an answer.[/quote]Yup true not the mtd prone it is the child..like mine very likely will have error.
Wow thank you, nice..algebra will be more prone to mistakes for some kids? think there is a reason to teach kids on model mtd..interesting.MrsKiasu\" post_id=\"2044908\" time=\"1636035400\" user_id=\"43981:
[quote=floppy post_id=2044907 time=1636035008 user_id=97579]
Let x be the number coins.
Helen has
[(x-64)*0.5 + 64*0.2]
= 0.5x - 32 + 12.8
= $(0.5x -19.2) in coins... (1)
Ivan has
[(x-104)*0.5 + 104*0.2]
= 0.5x - 52 + 20.8
= $(0.5x - 31.2) in coins... (2)
Comparing (1) and (2), Helen has more money in coins.
She has [(0.5x -19.2) - (0.5x -31.2)]
= 0.5x - 19.2 - 0.5x + 31.2
= $12 more in coins.
By the way, the last part has nothing to do with algebra.
Given that Helen and Ivan has the same number of coins (x), Helen must have 40 more 50 cents coins than Ivan (104 - 64).
Therefore, Ivan coins would weight [1.134 - (40 x 2.7)]
= 1.134 - 0.108
= 1.026 kg
Thank you. You are welcome. -
MrsKiasu\" post_id=\"2044908\" time=\"1636035400\" user_id=\"43981:
Wow thank you, nice..algebra will be more prone to mistakes for some kids? think there is a reason to teach kids on model mtd..interesting.[/quote]Yes, the reason is that the model method is much shorter and easier to use on this sort of questions for children. And it is also easier to learn as they are more visual.
Let x be the number coins.floppy\" post_id=\"2044907\" time=\"1636035008\" user_id=\"97579:
[quote=Veyron post_id=2044897 time=1636032263 user_id=30663]Parents need to be mindful when trying to introduce algebra to P6es because the algebra they are taught in school are very basic and they are not equipped to solve challenging math problems using algebra.
Those who swear by the algebra being the gold standard, can you demonstrate how to solve this PSLE question
Helen and Ivan had the same number of coins. Helen had a number of 50-cent coins and 64 20-cent coins. Helen's coins had a total mass of 1.134kg. Ivan had a number of 50-cent coins and 104 20-cent coins.
(a) Who has more money in coins and by how much?
(b) Given that each 50-cent coin is 2.7g more heavier than a 20-cent coin, what is the mass of Ivan's coins in kilograms?\"
Helen has
[(x-64)*0.5 + 64*0.2]
= 0.5x - 32 + 12.8
= $(0.5x -19.2) in coins... (1)
Ivan has
[(x-104)*0.5 + 104*0.2]
= 0.5x - 52 + 20.8
= $(0.5x - 31.2) in coins... (2)
Comparing (1) and (2), Helen has more money in coins.
She has [(0.5x -19.2) - (0.5x -31.2)]
= 0.5x - 19.2 - 0.5x + 31.2
= $12 more in coins.
By the way, the last part has nothing to do with algebra.
Given that Helen and Ivan has the same number of coins (x), Helen must have 40 more 50 cents coins than Ivan (104 - 64).
Therefore, Ivan coins would weight [1.134 - (40 x 2.7)]
= 1.134 - 0.108
= 1.026 kg
Thank you. You are welcome.
Years ago, quite a lot of children had difficulty learning algebra. The ministry did some study and research before implementing the model method. It is useful for young children in primary school. I think because they teach model method, they want to test model method. The only way is to have questions that are easier to solve using model method. (Else everyone use algebra) A well-learned kid will use model instead as it’s more efficient… less careless mistakes compared to using algebra, which can be complicated to some children. -
MrsKiasu\" post_id=\"2044912\" time=\"1636036253\" user_id=\"43981:
Yup true not the mtd prone it is the child..like mine very likely will have error.[/quote]Not the child, but the level of familiarity with these two methods.
No. I don’t think one will be more prone to mistakes in one method or another if they are equally well versed in both. The problem with algebra is having a statement that includes a variable like Helen has $(0.5x -19.2). I think some kids will have some discomfort not having a “whole number” or stating the variable as part of an answer.floppy\" post_id=\"2044911\" time=\"1636035906\" user_id=\"97579:
[quote=MrsKiasu post_id=2044908 time=1636035400 user_id=43981]
Wow thank you, nice..algebra will be more prone to mistakes for some kids? think there is a reason to teach kids on model mtd..interesting.
Algebra is being taught quite late in the syllabus and it is only 1 chapter out of the whole math textbook. Unless the child has tuition or someone at home teaching or guiding, child is unlikely to be well versed in it. -
Let the number of 50ct coins Helene has be H.
Let the number of 50ct coins Ivan has be I.
Since both Helene and Ivan have the same number of coins, we can form the equation:
H+64 = I+104
H = I+40
The amount of money Helene is Hx$0.5 + 64 x $0.2 = $0.5H + $12.80
The amount of money Ivan has is I x $0.5 + 104 x $0.2 = (H-40)x$0.5 + 104 x $0.2 = $0.5H + $0.8
Comparing the two amounts, Helene has more money and she has ($0.5H + $12.8 - $0.5H - $0.8) = $12
Part (2):
Let the weight of a $0.2 coin be w, then the weight of a $0.5 coin is w+2.7
Helen’s coins has a weight of 1134g, we can form the following equation:
H x (w+2.7) + 64w = 1134
H x w + 2.7H + 64w = 1134
For Ivan, the total weight of his coins is I x (w+2.7) + 104w
= (H-40)x(w+2.7) + 104w
= H x w + 2.7H - 40w - 108 + 104w
= H x w + 2.7H + 60w - 108
= 1134 - 108
= 1026 -
lee_yl\" post_id=\"2044921\" time=\"1636037181\" user_id=\"17023:
If dd learned this during Pri level, she won't suffer this much now.. but I think she may have issues solving this type of problems due to carelessness.
Let the number of 50ct coins Helene has be H.
Let the number of 50ct coins Ivan has be I.
Since both Helene and Ivan have the same number of coins, we can form the equation:
H+64 = I+104
H = I+40
The amount of money Helene is Hx$0.5 + 64 x $0.2 = $0.5H + $12.80
The amount of money Ivan has is I x $0.5 + 104 x $0.2 = (H-40)x$0.5 + 104 x $0.2 = $0.5H + $0.8
Comparing the two amounts, Helene has more money and she has ($0.5H + $12.8 - $0.5H - $0.8) = $12
Part (2):
Let the weight of a $0.2 coin be w, then the weight of a $0.5 coin is w+2.7
Helen’s coins has a weight of 1134g, we can form the following equation:
H x (w+2.7) + 64w = 1134
H x w + 2.7H + 64w = 1134
For Ivan, the total weight of his coins is I x (w+2.7) + 104w
= (H-40)x(w+2.7) + 104w
= H x w + 2.7H - 40w - 108 + 104w
= H x w + 2.7H + 60w - 108
= 1134 - 108
= 1026 -
Zeal mummy\" post_id=\"2044917\" time=\"1636036760\" user_id=\"58173:[quote=\"Zeal mummy\" post_id=2044917 time=1636036760 user_id=58173]
MrsKiasu\" post_id=\"2044908\" time=\"1636035400\" user_id=\"43981:
Yes, the reason is that the model method is much shorter and easier to use on this sort of questions for children. And it is also easier to learn as they are more visual.
Years ago, quite a lot of children had difficulty learning algebra. The ministry did some study and research before implementing the model method. It is useful for young children in primary school. I think because they teach model method, they want to test model method. The only way is to have questions that are easier to solve using model method. (Else everyone use algebra) A well-learned kid will use model instead as it’s more efficient… less careless mistakes compared to using algebra, which can be complicated to some children.Looks like both are important..
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