rgps seminar for parents (revised)
DESCRIPTION
This is the presentation made to 200 parents in Raffles Girls' Primary School in Singapore. It was organized by the alumni members.TRANSCRIPT
Using The Model Method to Solve Word Problems
Dr Yeap Ban HarMarshall Cavendish Institute
Singapore
Slides are available at www.banhar.blogspot.com
Collegio Dagoberto Godoy, Santiago de Chile
The Curriculum (Ministry of Education 2006)
The Curriculum (Ministry of Education 2006)
emphasis thinking
emphasis visualization
122 xx
Experiencing Singapore Math
Experiencing Singapore Math
Experiencing Singapore Math
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 1 3 units 1518 units 6 x 15 = 60 + 30 = 90
Method 2 3 units 15 1 unit 518 units 18 x 5 = 50 + 40 = 90
18 units 6 x 15 = 3 x 30 = 90
18 units 18 x 5 = 180 ÷ 2 = 90
$18
$24 ÷ 3 = $8 Allan’s allowance = 4 x $8 = $32
$6
Mon
Tue $3
Wed $3 $3
Thu $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.
$3
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.
apples
oranges 90
pears
38
What if we have drawn 38 to be much longer?
15
apples
oranges 105
pears
38
What if we have drawn 38 to be much longer?
We still get 5 units 105
One other way to solve it …
Number of oranges left = xNumber of apples left = 2xNumber of pears left = 2x – 15
x + 2x + 2x – 15 = 905x = 105 x = 21
Number of pears left = 2 x 21 – 15 = 27Number of pears at first = 38 + 27 = 65
Number of oranges at first = 65Number of oranges used = 65 – x = 65 – 21 = 44
342
18%
24%
76%
76% 342
1% 4.5
100% 450
Mr Wong had 450 books at first.
Jane + Xueling Siti
Xueling + Siti (64)Jane (16)
(24)
(24 – 16) units = 8 units
(40)
8 units = 14 shells
40 units = 5 x 14 shells
40 units = (50 + 20) shells
Xueling collected 70 shells.
This problem requires the ability to visualize.
b
d
xx + b + d = 180
c
e y y + c + e = 180
By the same logic:• x + b + d = 180• y + c + e = 180• z + a + d = 180• v + b + e = 180• w + a + c = 180
a
b
cd
e x y
z
v
w
2a + 2 b + 2c + 2d + 2e + x + y + z + v + w = 5 x 180
x + y + z + v + w = 3 x 180
Hence, a + b + c + d + e = 180
Using The Model Method to Solve Word Problems
Dr Yeap Ban HarMarshall Cavendish Institute
Singapore
Slides are available at www.banhar.blogspot.com
Using The Model Method to Solve Word Problems
Slides are available at www.banhar.blogspot.com
Mani has 245 ten-cent coins and
455 five-cent coins. Nina has
165 ten-cent coins and 135 five-
cent coins. After Mani gives
Nina some coins, of Mani’s
coins are ten-cent ones and the
ratio of the number of Nina’s
five-cent coins to the number of
her one-cent coins is 3 : 2.
They have only five-cent and
one-cent coins.
5
1
Find the number of coins Mani gives to Nina.
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