Workshop 3

1. Using Bar Model to Solve Word Problems
involving whole numbers, fractions, ratios and
algebra
Harris Federation, London  October 2012
Yeap Ban Har
Marshall Cavendish Institute
Singapore
yeapbanhar@gmail.com
Slides are available at
www.banhar.blogspot.com

2. Mathematics is “an excellent vehicle for the
development and improvement of a person’s
intellectual competence”.
Ministry of Education Singapore 2006

3. Ratio  Example 1
Larry
Maria
4 units = $300
1 units = $300  4 = $75 King Solomon Academy, London
3 units = 3 x $75 = $300 - $75 = $225
Maria gets $225.

4. Edgewood Elementary School, New York

5. Whole Numbers  Example 2
John has $34 more than Mary.
Together, they have $100.
How much money does each of them have?
Royston Primary School, London
John $34
Mary
$100 - $34 = $66
$66  2 = $33
Mary has ….
John has ….

6. John x $34
Mary x
2x + 34 = 100
2x = 100 – 34 = 66
x = 66  2 = 33
Royston Primary School, London

7. Learning Activity  Example 3
1

4 10
1 1

4 4 8
1

4 20

8. GCSE  Example 4 4 x £3600 = £12000 + £2400 = £14400
Last year Jora spent 3 6
30%  
10 20
30% of his salary on rent
2 4 8
 
2 5 10 20
of his salary on entertainment
5 1 5

1
of his salary on living expenses. 4 20
4
6 8 5 19
He saved the rest of his salary. Jora spent:   
20 20 20 20
19 1
Jora spent £3600 on living expenses. Jora saved: 1 
20 20
Work out how much money he saved. £14400  20 = £1440  2 = £…..

9. GCSE  Example 4
Last year Jora spent
30% of his salary on rent 5 units =£3600
2 1 unit = £3600  5
of his salary on entertainment
5 = £360 x 2
1 = £720
of his salary on living expenses.
4
He saved the rest of his salary.
Jora spent £3600 on living expenses.
Work out how much money he saved.

10. PSLE  Example 5

11. GCSE  Example 5
7
Peili Peili
Nurul Nurul
7
After … 7
Before …

12. Additional Example on Using Bar
Model and Number Line to Solve
Linear Equations

13. Equations  Example 6
3y + 1 = 2
Solve 7 – 3y = 1 .
7
3y = 2 – 1
3y = 1
3y 1

14. Solve 7 – 3y = 1 .
3y = 6
3y 7
1

15. GlobeAcademy, London

17. emphasis
visualization