P5/P6 Workshop for Parents -Mathematics - Poi Ching School
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Transcript of P5/P6 Workshop for Parents -Mathematics - Poi Ching School
PSLE Examination Format 2019 - SMA
Paper Booklet Item Type Number of questions
Number of marks per question
Weighting Duration
1A
Multiple-choicequestions
10 1 10%
1 hour5 2 10%
BShort -answer
5 1 5%
10 2 20%
2Short-answer 5 2 10%
1 h 30 minStructured/Long-answer 12 3, 4, 5 45%
Total 47 100% 2h 30 min
- Students are allowed to use calculator for Paper 2 only. - There will be a break in between Paper 1 and Paper 2.
PSLE Examination Format 2019 - FMAPaper Booklet Item Type Number of
questionsNumber of marks per question
Weighting Duration
1A
Multiple-choiceQuestions
10 1 10%
1 hour10 2 20%
BShort-answer questions
10 2 20%
2Short-answer questions
10 2 20%1 hour
Structured/Long-answer questions
6 3 , 4 20%
Total 46 90% 2 hours
- Students are allowed to use calculator for Paper 2 only. - There will be a break in between Paper 1 and Paper 2.
2
11
6
9
6
5
6
4
6
5
3
2
Do not stop at improper fraction unless it is instructed
Common Error
Addition & Subtraction of Fractions
• Always leave final answer in simplest form
Division of Fractions
4
3
8
6
8
5
5
6
8
5
6
5
• Incorrect inverting of the dividend instead of divisor
3
11
3
4
6
8
5
8
6
5
8
5
6
5
• Keep the first fraction
• Flip(Invert) the second fraction (find the reciprocal)
• Change the operation sign ( ÷ to x )
Division of Fractions
25
231
25
48
5
8
5
6
8
5
6
5
• Incorrect inverting of both the dividend and divisor
3
11
3
4
6
8
5
8
6
5
8
5
6
5
• Keep the first fraction
• Flip(Invert) the second fraction (find the reciprocal)
• Change the operation sign ( ÷ to x )
Equivalent Fractions
20
155
4
3
• Should multiply both numerator and denominator with the same factor
20
15
4
3
5
5
Word Problems involving fractions
Take note of the following. Do not misread the questions.
• I had 2 kg of flour. I used 𝟏
𝟓kg of it to bake a cake. How
much flour had I left in the end?
• I had 2 kg of flour. I used 𝟏
𝟓of it to bake a cake. How much
flour had I left in the end?
2 −1
5= 1
4
5
2 ×1
5=2
52 −
2
5= 1
3
5
Unknown Angles
• Wrong assumptions thinking that it is isosceles triangle which is not stated in question
∠𝑐 + ∠d -----------
∠𝑎 + ∠b -----------
Unknown AnglesABCD is a parallelogram. EG = EF and GF is parallel to AB and DC.
Find ∠x and ∠y.
• Wrong assumptions thinking that ∠ADE and ∠EDC are equal
Unknown Angles
• Angles obtained are shown clearly in the diagram
70°
70°
Method mark will be awarded accordingly even though the final answer is incorrect as there is clear indication shown in the diagram
Errors involving Units
•Money ‘$’• $12.9 (x)
• Must have 2 decimal places
• $12.90 ()
• $54 – 90¢ = $53.10 (correct presentation)
• 54 – 90 = 53.10 (incorrect presentation due to missing units)
• Change all numbers to the same units in the equation
• This also applies to mass, length, time etc. which involve different set of units
•Percentage ‘%’• 50% % (incorrect as there is a change in value, 50% % = 0.5%)
Misuse of Equal Sign
•10% = 50 (inappropriate presentation as value is different)
•10% ---- 50 (appropriate presentation)
•2
3+ 5
6=
4
6=
4
6+ 5
6=
9
6= 1
3
6= 1
1
2(x)
•2
3+ 5
6=
4
6+ 5
6=
9
6= 1
3
6= 1
1
2()
• 4 + 3 x 9 = 4 + 27
= 31
Inappropriatepresentation
Appropriatepresentation
Understand the word problem
Decide an approach
Go through ‘Decision Guide’
Solve the word problem using selected approach
Understand the word problemNot OK
END
OK
SPAR framework
See
Plan
Act
Reflect
Decision guide
Easily represented using model/ diagram?
Table or series of numbers/ diagrams?
Two or more quantities (unknowns) linked in more than one way?
Stated range or multiples? (“How many ways of arranging…”)
Has a result or relationship?(“First this… Then this…”)
No
No
No
No
H1 – Model/ Diagram
H2 – Find a pattern
H3 – Substitution
H4 – Make-a-list
H6 – Working Backwards
H5 – Guess and Check
Yes
Yes
Yes
Yes
YesNo
H1: Model Drawing
Relate the word
problem with the model
diagram to help students
visualize the question
better.
[ PSLE 2015 Paper 2 Q7 ]
At first, Ben had $90 and Chandra had $48. Each bought a shirt at the same price. The amounts of money Ben and Chandra had left were in the ratio 4 : 1. How much did the shirt cost?
3u = 90 – 48 = 42
1u = 42 ÷ 3= 14
48 – 14 = 34
Ans: $34
H1: Model Drawing
[ PSLE 2017 Paper 2 Q3 ]
Mrs Lee had a bottle of orange juice. She drank 600 ml of the juice in the morning
and 1
6of the remaining juice in the afternoon. After that, there was
1
2a bottle of
juice left. How much of the juice did she drink in the afternoon?
4u = 600
1u = 600 ÷ 4= 150
Ans: 150 ml
half amt left
600 ml
half amt drank
remaining
Sets of 4 digits
H2: Finding a Pattern
4 , 0 , 1 , 2 , 4 , 0 , 1 , 2 , 4 , 0 , 1 , 2 , 4 , 0 , 1
[ PSLE 2017 Paper 2 Q8 ]
The first 15 numbers of a number pattern are given below.
4 , 0 , 1 , 2 , 4 , 0 , 1 , 2 , 4 , 0 , 1 , 2 , 4 , 0 , 1 , …1st 15th
Find the 626th number. Find the sum of the first 627 numbers.
627 ÷ 4 = 156 r 3
4 + 0 + 1 + 2 = 7 (sum of a set)
156 x 7 = 1092
1092 + 4 + 0 + 1 = 1097
Ans: 1097
626 ÷ 4 = 156 r 2
Ans: 0sets
pattern starts again
pattern starts again
H2: Finding a Pattern
Relate the solution with respect to the
pattern no.
[ PSLE 2016 Paper 2 Q18 ]
Yasmin uses triangles and circles to form figures that follow a pattern as shown below.
A figure in the pattern has a total of 100 triangles and circles. What is the figure number?
Fig. No. 1 2 3 4
No. of 2 5 9 14
No. of 2 4 7 11
Total no. 4 9 16 25
Another figure in the pattern has 50 more triangles than circles. What is the total number of triangles and circles in this figure?
Total no. 42 x 2
93 x 3
164 x 4
255 x 5
Fig. No. 1 2 3 4100 = 10 x 10 10 – 1 = 9 (Figure No.)
Fig. No. 1 2 3 4
No. of 2 5 9 14
No. of 2 4 7 11
Find difference2 – 2 = 05 – 4 = 19 – 7 = 214 – 11 = 3
Diff = 50Fig – 50 + 1 = 51Total = 52 x 52
= 2704
Relate the solution with respect to the
pattern no.
H3: SubstitutionAt a bakery, Jen paid $12.40 for a banana cake and 4 egg tarts. Shan paid $25.20 for a
banana cake and 20 egg tarts. Rani bought 5 banana cakes. How much did she pay?
[ PSLE 2013 Paper 2 Q9 ]
1 C + 20 T = 25.21 C + 4 T = 12.4---------------------------------
16 T = 25.2 – 12.4= 12.8
4 T = 12.8 ÷ 4= 3.2
1 C = 12.4 – 3.2= 9.2
5 C = 9.2 x 5= 46
Ans: $46
H3: SubstitutionYulin wants to make 14 small identical stars and 20 large identical stars using wire. She has made 12 small stars and 7 large ones using 960 cm of wire. The length of wire she used for 3 large stars is the same as that for 4 small stars.
[ PSLE 2014 Paper 2 Q17 ]
4s --- 3L12s -- 9L
× 3
12s + 7L = 9609L + 7L = 960
16L = 960
L = 960 ÷ 16= 60
How many large stars can be made with the same length of wire used to make 12 small stars?
What is the length of wire she needs to make the remaining stars?
13L = 60 × 13= 780
3L = 60 × 3= 180
2s = 180 ÷ 2= 90
4s --- 3L
780 + 90 = 870
Ans: 870 cm
H4: Make-a-list
Multiples of 8Multiples of 8
+ 2Multiples of 9 Multiples of 9
- 2
170 ÷ 8 = 21 R 2
Try 22 × 8 = 176
176 178
184 186
192 194
200 202
170 ÷ 9= 18 R 8
Try 19 × 9 = 171
171 169
180 178
BINGO !!!We have a
match! Ans: 178
Catherine has a bag containing between 170 to 200 coins. When she arranged them into stacks of 8, she has 2 coins extra. When she arranged them into stacks of 9, she has 2 coins short. How many coins are there in the bag?
H6: Working BackwardsA bus left an interchange carrying some passengers with it.
At the first stop, ¼ of the people in it alighted and 5 people boarded it.
At the 2nd stop, ½ of the people in it alighted and 20 people boarded the bus.
When it left the 2nd stop, there were 60 passengers in it.How many passengers were there in the bus when it left the interchange?[ http://www.singaporemathguru.com/blog/working-backwards-with-fractions/ ]
@ Interchange
@ 1st Bus Stop
@ 2nd Bus Stop
5
20
?
Working backwards from the 2nd Bus Stop
60
60 – 20 = 40
40 × 2 = 80
80 – 5 = 75
75 ÷ 3 = 25
25 × 4 = 100
Ans: 100
H5: Guess-and-check
Meng sold a total of 368 large and small durians at the prices shown below and collected $2760. How many large durians did Meng sell?
[ PSLE 2013 Paper 2 Q15 ]
No. of Large No. of Small Total ($) / ×
184 184 184 x 9 + 184 x 5 = 2576 x
2760 – 2576 = 184 (difference in amt)9 – 5 = 4 (diff bet. 1 L and 1 S durian184 ÷ 4 = 46 (need to top up 46 L)
230 138 230 x 9 + 138 x 5 = 2760
Assumption Method (Alternative solution)Assume all small durians
368 x 5 = 18402760 – 1840 = 920
920 ÷ 4 = 230
Assume all large durians368 x 9 = 3312
3312 – 2760 = 552552 ÷ 4 = 138
368 – 138 = 230
Examination Time Management Strategy for PSLE Math Paper 1- Time Allocation
• Total duration: 1 hour
Paper 1- Booklet A- MCQ: 10 qns- 10 min
5 qns-10 min
Booklet B- Short Answer qns: 5 qns- 5 min
10 qns- 20 min
Total time taken- 45-50 min
Checking- 10-15 min
Rule of thumb :
1 mark qn - 1 min
2 mark qn - 2min
Revision Tips
•Important things to take note • Spelling of words eg. forty, ninety, million• Use of hyphen for numbers like twenty-one, fifty-nine etc.• Order of operations • Area and perimeter of square and rectangle• Area of triangle• Average• Properties of 4-sided figures• Speed• Volume• Area and Circumference of Circles• Multiplication tables of 2 to 9
Revision Tips
•Use calculator only when you see
•Do remind your child to write down every step clearly.
•All workings/equations/steps are essential.
•Your child’s final answer may be incorrect, but he/she can still obtain some marks for showing the correct workings/equations/steps.
•Ensure that your child has cultivated the habit of checking the reasonableness of their answers.
Revision Tips
•Ensure your child has exposure to questions on all the topics to be tested.
•Run mock examinations at home and time him/her.
•As PSLE approaches, your child should be revising instead of learning new concepts.
Revision Tips
•As the saying goes, “Practice makes perfect!”, encourage your child to practise consistently for the PSLE.
• Learn from the mistakes made and try out the problems again to build confidence.
•Taking short breaks in between the study sessions is crucial.
Examination Tips – Multiple Choice Questions
•Highlight the keywords / key information
• Look for the ‘negative’ keywords in the questions • not or incorrect
•Do the calculation and working for easy checking later
•Write down the options selected in the booklet before shading
• Shade the OAS carefully with the answers matching the respective questions
• Eliminate any impossible answers
• Substitute the options chosen into the questions to check for reasonableness
• Circle the question number if decide to skip first
Examination Tips – Short/Long Answer Questions
•Highlight the keywords / key information•Questions involve Geometry, mark the necessary
information in the diagram shown• Angles• Length
•Plan and organise the solutions for easy checking later•Draw model to help visualise the questions•Apply any of the heuristics skills learnt• Guess & Check / Working Backward
•Transfer the numbers/digits correctly from the questions and throughout the steps•Minimise transfer error/misread
•Circle the question number if decide to skip first
Examination Tips – Short/Long Answer Questions
•Perform the operation (add/subtract/multiply/divide) carefully•Write in complete equations and be consistent in the
units•Answers given in fractions/ratios must be in the
simplest form•Check if rounding (1 or 2 d.p.) is required when
answers are in decimals•Work backwards with the answers obtained to check if
they satisfy the conditions given in the questions•Provide with a standard unit of measurement at the
final answer line unless the unit is already been given• Avoid 19% %