Pembagian Pecahan Pendidikan Matematika Realistik

Modul VII
Pembagian Pecahan
Pendidikan Matematika Realistik

oleh: Marsigit
Reviewed by Kartiko Rachman YP 09313244006

The main idea from RME starts from the contextual problem, giving problem near students’ life. The contextual way is the base of the iceberg theory that starts from contextual and abstract in the end.
For the example: someone who has 75 kg sugar will put that sugar in to little box that contain 500 g in average. How many boxes he need to divide 75 kg sugar into 500 g sugar?
The answer instantly we get (75 : ½ ). However, we need the way how we can calculate, how we get that the answer is (75 : ½ ), because the (75 : ½ ) is in the top of iceberg whereas we will do the problem start from the contextual and think logically. The way to answer can be shown as a picture, not only as number with an operator.


the number of ? | ? | ? | ? | ? | … … … | ? |
boxes needed ? | ? | ? | ? | ? | … … … | ? |
| | | | | … … … | |
kilogram(s) sugar 1 | 2 | 3 | 4 | 5 | … … … | 75 |

if we jump the step from 1,2,3,4,5,...,75 we still have abstract condition here, that is assume ... ... ... to be value number 6 until 74, but this assumption will help students think logically. From the picture, we see clearly that each kilogram,every one kilogram, need two boxes. Then, we can make a sequence "if we take one kilogram we need two boxes, if we take two kilograms we need 4 boxes and so on" mathematically we wrote:

kilograms 1 2 3 4 5 ... 75
boxes 2 4 6 8 10 ... 150
So, by this step of thinking, we not only get the result, but we also think logically how we can do division between integer and fraction.