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.
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?
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
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).
85名学生组成85÷17 = 5组学生，5组学生共享5×12 = 60粒苹果。
練習題 : PSLE（16/02/2015).