Ho Soo Thong

The following problem is a variant of a recent examination question ( PSLE 16/02/2015 ). The solution to this question involves a heuristic bar modelling process of finding visually the LCM (Least Common Multiple) of two numbers for satisfying a certain situation.

Sharing Apples

There were a total of 85 pupils sharing some apples.
A package of three apples for four girls A package of two apples for three boys
The girls and the boys shared equal number apples.
How many apples were there?
Solution
First, we constructs bar models to depict the sharing situations.

Next, we construct a bar model to depict the least possible number for the situation:

The girls and the boys shared equal number apples

The bar model shows that 6 ( = 2×3 ) is the least equal number.

Now, we add a bar model to show the corresponding number of pupils as a group of 17 (= 2×4 + 3×3).

There are 85÷17 = 5 groups of pupils and so there are 5×12 = 60 apples.

Note : you may practice with PSLE 16/02/15

分享苹果问题- 杆模型方法

以下是一个具有挑战性的小学应用问题,数学情況涉及寻找两个数字的最小倍数(Least Common Multiple).

分享苹果问题

共有85名学生分享一些苹果。 

四个女孩分享三粒苹果 三个男孩分享两粒苹果

女生和男生共享相同数量的苹果。

共有几粒苹果?

题解

第一个步骤 : 

构建杆模型来描述两个情境:

第二个步骤 :

用以上两个情境构建一个对应的杆模型。

85名学生组成85÷17 = 5组学生,5组学生共享5×12 = 60粒苹果。

以上展示了基本数学的应用,

練習題 : PSLE(16/02/2015).