nctm2011 afternoon session

SINGAPORE MATHBar Model Method

Dr Yeap Ban HarMarshall Cavendish Institute

Singapore

banhar@sg.marshallcavendish.com

Slides are available at www.banhar.blogspot.com

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MCI-WSU Singapore Math Summer Institute 6 – 8 July 2011

Comprehensive program taught collaboratively by Singapore mathematics educators and

WSU’s professors.

The Curriculum (Ministry of Education 2006)

Kyla

Jake $9

$28

?

?$28 – $9 = $19

Kyla has $19.

Ming

Naomi

48

48 ÷ 4 = 12

Ming has 36 candies.

3 x 12 = 36

apples

15

3 units 1518 units 6 x 15 = 90

There are 90 fruits in the basket.

Method 13 units 15

18 units 6 x 15 = 60 + 30 = 90

Method 23 units 151 unit 5

18 units 18 x 5 = 50 + 40 = 90

18 units 6 x 15 = 3 x 30 = 90

18 units 18 x 5 = 180 ÷ 2 = 90

QuestionWhat if the fraction is such it is not easy to split the remainder part?

See the example presented in the morning session.

Allan spent ¼ of his allowance on a gift and ¼ ofthe remainder on a book. The book cost $18.Find the amount of Allan’s allowance.

4 x $18 = $72

$72 ÷ 3 = $24 Allan’s allowance = 4 x $24 = $96

Mon

Tue $3

Wed $3 $3

Thu $3 $3 $3

$100

$100 – 6 x $3 = $82

$82 ÷ 4 = $20.50

$20.50 + 3 x $3 = $29.50

She saved $29.50 on Thursday.

adults

children

2 units 380 – 260 = 120 1 unit 60

260 – 60 = 200200 + 200 = 400 400 people left at lunchtime.

apples

oranges 90

pears 15

38

apples

oranges 90

pears 15 23

apples

oranges ?

pears 15

90 + 15 = 1055 units

1 unit 105 ÷ 5 = 21

23

There were (21 + 21 + 23) apples, hence oranges.

There were 44 oranges used.

Extra ProblemFor you to try. Do not peek at the answer before you try it!

342

18%

24%

76%

76% 342

1% 4.5

100% 450

Mr Wong had 450 books at first.

MCI-WSU Singapore Math Summer Institute 6 – 8 July 2011

Comprehensive program taught collaboratively by Singapore mathematics educators and

WSU’s professors.