Upper Primary Mathematics Fractions - Commonwealth of Learning

Reflection
When illustrating an interpretation of a common fraction on a chalk board, do
you find it convenient to use a circle model? Why?
Length Model
Length models are similar to area models. The only difference is that lengths
are compared instead of area. In length models, we can compare number
lines and physical materials on the basis of length.
In the length models in Figure 1.4, common fractions are looked upon as
parts of a whole.
0
1
4
1
2
3
4
1
Number line
1
6
1
4
1
3
Folded paper strips
Figure 1.4 – Length models for fractions
Set Models
Set models also illustrate common fractions as part of a whole. The set of
objects make a whole, and subsets make up parts of the whole. The idea of
looking at a set of elements as a single entity contributes to making set
models difficult for primary pupils. Despite the difficulties faced by pupils,
we cannot do away with the set model interpretation of fractions because it
links real life situations to using fraction and ratio concepts. For instance,
four objects are two-thirds of six objects.
4
6
Figure 1.5: Set models for fractions
Module 2: Unit 1 6
Common Fractions
or
5
4
2
3