Q&A - PSLE Math
-
pixiedust:
Pixie dust,lizawa, thanks...but how to explain to P5/6 this step :
\"= 2u + 30 : 5u + 15
= 4 :7
7(2u +30) = 4 (5u+15)..\"
Brenda, no problem. If your dd has any other way to solve, do update too. thanks in advance.
You can explain in this way.
Draw 4 boxes and 7 boxes, like how u normally draw model for 4 : 7
The 4 boxes rep 2u+ 30 and 7 boxes rep 5u +15
to make both sets equal, I need 7 sets of 4 boxes and 4 sets of 7 boxes
Hence 7(2u+30) = 4(5u +15) -
1.noah and justin had a sum of money each.if noah gave justin $25.they would have the same amount of money .if justin gave noah $40. the ratio of the amount of money noah had to the amount of money justin had would be 7:2 how much money did justin have?
2.ali and imran had 224 game cards. During the first game, imran lost1/3 of his cards ti ali.At the second game,Ali lost3/7 of his cards to imran.Then they had the same number of cards left.How many game cards did imran have at first?
how to solve this sum pls help -
raghupavithra:
Q11.noah and justin had a sum of money each.if noah gave justin $25.they would have the same amount of money .if justin gave noah $40. the ratio of the amount of money noah had to the amount of money justin had would be 7:2 how much money did justin have?
how to solve this sum pls help
If noah gave justin $25,they would have the same amount of money
N [------------][25][25]
J [------------]
N [-------][40][25][25]
J [-------][40]
If justin gave noah $40 , the ratio of the amount of money noah had to the amount of money justin had would be 7:2
N [-------] [40][25][25][40]
J [-------]
2u --> [-------]
5u --> [40][25][25][40] = 130
1u --> 26
[-------][40] --> 2u + 40 = 2*26 + 40 = 92
Justin had $92 (Ans) -
raghupavithra:
Q2
2.ali and imran had 224 game cards. During the first game, imran lost1/3 of his cards ti ali.At the second game,Ali lost3/7 of his cards to imran.Then they had the same number of cards left.How many game cards did imran have at first?
how to solve this sum pls help
they had the same number of cards left
A 4u
I 4u
Before Ali lost3/7 of his cards to Imran ,
A 4u+3u = 7u --> 14u
I 4u-3u =1u --> 2u
Before Imran lost1/3 of his cards to Ali
A 14u-1u = 13u
I 2u+1u = 3u
At first , the no. of game cards that Imran had = 3/16 * 224 = 42 (Ans) -
pixiedust:
Tianzhu, do you agree the UP method is \"easier\" and \"faster\" for this problem ?
Hi pixiedust
Good Morning.
MD is one of many problem solving heuristics taught in primary schools, it enables a child to “see” Maths. However at times, it may be a little bit challenging or cumbersome to use MD depending on the numbers given in the question. During such times, it would be beneficial if a child is exposed to alternative strategy such as UP.
Besides MD and UP, you may also solve your question with “Systematic Listing” (SL).However, it is less efficient that MD and UP. In using SL, a child uses a tabulated list to arrive at the answer.
Expose a child to as many strategies (within syllabus) as possible and let him decides on the method he prefers to use to solve a question.
Best wishes -
![](\"http://i53.tinypic.com/2h6abzc.jpg\")
http://i53.tinypic.com/2h6abzc.jpg\"> Hi Can someone advise what is the sum of angles a, b, and c shown in the picture? Thanks in advance.
-
jesschan:
Hi
are there any information missing ?
cheers. -
jesschan:
You didn't specify if there are any straight lines in the figure. Assuming that the 2 lines passing angle C are straight lines, then the answer should be 2c.
The 2 unknown angles are (180 -c) x 2 = 360 - 2c
Sum of a,b,c = 360 - (360-2c) = 2c. -
Hi lizawa,
All the lines drawn are straight lines, meaning a+b = c since they are vertically opp angles. But other than that, no info was given. Answer is 300 degrees. -
Hi… Can someone pls help with this question - thanks!
Linda mixed 3 l of blue paint with 7 l of white paint. She then poured out 4 l of the mixture into a pail and added 6 l of red paint into the pail. Find the ratio of the volume of blue paint to the volume of red paint in the pail.
Hello! It looks like you're interested in this conversation, but you don't have an account yet.
Getting fed up of having to scroll through the same posts each visit? When you register for an account, you'll always come back to exactly where you were before, and choose to be notified of new replies (either via email, or push notification). You'll also be able to save bookmarks and upvote posts to show your appreciation to other community members.
With your input, this post could be even better 💗
Register Login