# Bar Model Approach to PSLE-2019 Questions

Ho Soo Thong Ho Shuyuan

In 2019 PSLE Examination, pupils encountered quite a number of challenging math questions. Here, we intend to highlight the basic mathematics in the Holistic Bar Modelling Approach to three questions.

A holistic bar model enables us to have an overview of the solution and see the challenging level of the question.

**Question 1**

*Remark* : The question involves three related “Fraction”situations. There is a complex algebraic relation 3X = 7Y for which we apply the *Greatest Common Unit Procedure*.

*Alternatively*, we can use the *Euclid’s Line-Segment Approach* together with an algebraic symbol U as shown below.

**Question 2**

*Remark *: A challenging *Distributive Problem* involves the algebraic relation

*Cost = number of units × unit cost. *

The solution apply *Distributive Law* for deductive approach.

**Question 3**

Remark : The question is quite challenging to pupils. It involves a sequence of numbers and *Algebra* for a *Sum-difference *situation.