Primary Mathematics

Modelling Approach

The example of a moelling questios and solution

1) The part-whole model
We use this model on problems which :
a) requires us to fin the whole give both parts of a quantity

<-------------------?--------------->
__________________________
| known | known |

b) require us to find out one part of a quantity given the whole and another part of the quantity

<-----------------known------------>
___________________________
| known | ? |


2 The comparison model
This model shows the relationship between 2 quantities. We use this model on problem which :
a) involve a difference between two quantities

A : ______________________
| |

B : ________
| | <------difference->

b) involve a ratio between 2 quantities

A: __________________
| | | |
<-------3 units--------->
B : _____
| |
<--1 unit

3) The 'change' model
This model shows the relation between the new value and the original value of a quantity

Before : _____________________
| |

After ______________________________
| | Addition |

Other technique that can be applied other than modelling are guess and check, making a systematic list, etc, could be used.


Example of a question and solutions :
Eric is 10 and his mother is 42. In how nmany years ' time will his mother be 3 times as old as him ?

Solution
At present :
Eric's age ________
| 10 years |<------ difference 32-->
Mother's age _________________________
| 42 years |

Some years later
Eric's age _________________
| 10 years | some years|<------ difference 32-->
<-------1 unit----------->

Mother's age __________________________________
| 42 years | some years|
<-------- 3 units ------------------------------->

So, 3 units - 1 unit = 32 years
2 units = 32 years
1 unit = 16 years
Hence, in (16-10) years, which is 6 years time, Eric's father will be 3 times as old as him



Technorati Profile

posted by Blogs @ 2:43 AM 0 Comments

Modelling Tecnique

Many students in primary schools are confused with the words questions that deal with modelling.

In my experience of coaching primary level students , they need proper guidance and patience.

A few pointers for the parents or students to take note of when to use modelling to resolve the problem sums.

1) When the question involves comparison for more than 2 items, which uses phrases such as "more than" and/or "less than"
2) When only a relative comparison is provided such as "the length of ruler A is twice the length of ruler B"

In general, when the above two scenerio occurs and when mental calculation is almost impossible, you could use model effectively to resolve the problems.

Next article will deal with more on the solution for modelling technique

posted by Blogs @ 8:56 AM 0 Comments