The Singapore Bar Model has been getting a lot of attention here in Queensland with some teachers and schools using it as the sole strategy for representing multiplication situations.
But it has limitations…
The Bar Model is similar to the Part Part Whole (PPW) model in that it can represent
- parts being added together to get the whole
- repeat addition of equal parts.
Part Part Whole
But there are two significant differences:
- The Bar Model lacks the symbols for addition and subtraction.
The symbols are crucial in enabling the students to identify the operation and subsequent number sentence – the underlying purpose of using the strategy in the first place.
- The Bar Model is used for representing multiplication situations.
And this is what I see as its major limitation.
Repeat addition of equal parts (skip counting etc) is the natural progression of student understanding from additive to multiplicative thinking and is suitable for Years 2 – 4 in Australian Curriculum.
However students who remain in an “additive thinking” will encounter major road blocks in the development of their mathematical understanding.
Try using the Bar Model to find 1.4kg of cherries costing $8.99 per kilogram….and this is what I see as its major limitation.
Students need to be show the necessity of identifying the number of groups and the amount per group and the relationship between them to enable them to solve all multiplicative situations. In my opinion – the best way to do this is through the use of the Multiplication & Division Triangle.