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This is the set of slides used at the seminar for Primary Five parents at Chongfu School in March 2011.
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Help Your Child in Problem-Solving
Heuristics
Dr Yeap Ban [email protected] Cavendish Institute
Singapore
www.banhar.com
Photo Credit: Students solving a mathematics problem using draw-a-diagram heuristic at Da Qiao Primary School.
Heuristics are rule of thumb that students can use to handle a problem when the solution is not obvious.
The problems used in the presentation are from PSLE Examination Questions Years 2006 – 2010 Mathematics published by Educational Publishing House Pte Ltd.
PSLE 2006 – 2010 Page 13 Question 45
Photo Credit: Primary 2 students at Woodlands Primary School using manipulatives to do multiplication and division.
PSLE 2006 – 2010 Page 13 Question 46
1.2 m x 42 = 50.4 m
43 – 6 = 37 There were 36 spacing
50.4 m ÷ 36 = 1.4 m
The new spacing was 1.4 m.
PSLE 2006 – 2010 Page 19 Question 58
Guess when each tried taking 11
33 Last girl had 11 sweets 41 Last girl had 8 sweets 49 Last girl had 5 sweets 57 Last girl had 2 sweets
PSLE 2006 – 2010 Page 19 Question 58
List 1 List 2
11 + 622 + 633 + 644 + 655 + 666 + 6
16 + 2524 + 2532 + 2540 + 2548 + 2556 + 25
PSLE 2006 – 2010 Page 19 Question 58
List 1 List 2
11 + 622 + 633 + 644 + 655 + 666 + 677 + 688 + 699 + 6
16 + 2524 + 2532 + 2540 + 2548 + 2556 + 2564 + 2572 + 2580 + 25
PSLE 2006 – 2010 Page 19 Question 58
3 x ? = 2 + 25
? = 9
There were 10 girls.
There were 9 x 11 + 6 = 8 x 10 + 25 = 105 sweets altogether.
PSLE 2006 – 2010 Page 19 Question 58
11m + 6 = 8(m + 1) + 25
Alternate Method8n + 25 = 11(n – 1) + 6
There were 10 girls. m = 9
n = 10
women
men 30
There were 4 x 30 = 120 men and women at first.
Photo Credit: Primary 2 students at Woodlands Primary School using the interactive board to learn independently and collaboratively.
Method 2Selecting 4 persons from a group of 5 is the same as to leave out one person from a group of 5.
There are 5 ways to leave out 1 person from a group of 5.Hence there are 5 ways to select 4 prefects from a group of 5 students.
Method 1Azlan, Bala, Chris, DarrenAzlan, Bala, Chris, EnlingAzlan, Bala, Darren, EnlingAzlan, Chris, Darren, EnlingBala, Chris, Darren, Enling,
38 + 57 = 95 2 fifths 38 peaches2 fifths 38 peaches1 fifth 19 peaches
3 fifths 3 x 19 pears = 57 pears
1 fourth = 3/12
1 third = 4/12
remainder= 5/12
5/12 95 fruits
1/12 19 fruits
There were 12 x 19 fruits or 228 fruits.
