Multiplicative thinking is indicated by a capacity to work flexibly with the concepts, strategies and representations of multiplication (and division) as they occur in a wide range of contexts.
In this section, you can find details about:
Multiplicative thinking is characterised by:
A student developing multiplicative thinking will move from a problem such as:
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3 bags of sweets, 8 sweets in each bag. How many sweets altogether?
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to problems such as:
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Julie bought a dress in an end-of-season sale for $49.35. The original price was covered by a 30% off sticker but the sign on the rack said, “Now an additional 15% off already reduced prices”. How could she work out how much she had saved? What percentage of the original cost did she end up paying?
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Students need to construct and coordinate three aspects of multiplicative situations when they are developing multiplicative thinking:
Students then need to move from the models and representations that work for whole numbers to more general ideas accommodating rational numbers and alge bra.
These more general ideas include:
This is a complex process and may take many years to achieve.
Multiplicative thinking begins to develop as each aspect (groups of equal size, the number of groups, and the total amount) is abstracted and can be dealt with as a mental object.
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MODELLED |
ABSTRACTED |
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Equal groups Makes all and counts all |
Trusts the count and sees equal groups as a composite unit |
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Number of groups Sees in terms of each group, counts all groups. For example: 1 group, 2 groups, 3 groups, ... |
Can deal with number of groups in terms of part-part-whole understanding. For example, 6 groups is:
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Total Arrived at by counting all and skip counting |
Total is seen as a composite of composites. For example, 18 is seen as :
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Working with concrete models and representations is important in the early stages. However, a key aspect in moving from modelling to abstracting appears to be the capacity to:
The move from additive to multiplicative thinking is not always smooth. It can be a real and persistent barrier to mathematical progress for students in the middle years of schooling.
Compared with the relatively short time needed to develop additive thinking, the introduction and exploration of ideas to support multiplication may take many years. According to some researchers, multiplicative thinking may not be fully understood by students until they are well into their teen years.
One way that we can move forward is to slow down and give students time to appreciate the complexities involved. This does not mean ‘dumb down’ but ‘think through’ problem situations by asking:
As teachers, we need a deeper understanding of what makes multiplication difficult and how we can scaffold more appropriate strategies.
Resources available through the Scaffolding Numeracy in the Middle Years (SNMY) project aim to provide further understanding about the transition from additive to multiplicative thinking.