nctm2011 afternoon session
DESCRIPTION
This session focuses on the use of the bar model to solve a range of problems. The presenter modelled a range of teacher behaviour to help students acquire the competencies that they are supposed to by engaging in word problems. It was presented at the Indianapolis conference. We hope not too many people were not able to get a seat at the session. If you were not able to gain entry to the session, please accept our apologies.TRANSCRIPT
SINGAPORE MATHBar Model Method
Dr Yeap Ban HarMarshall Cavendish Institute
Singapore
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.