How can a number line be used to
represent fractions?
The number line is a special type of length model.
Start by having the students identify the whole.
I know that the distance from 0 to 1 is one whole.
That's right! It doesn't matter how long we draw the line.
It's international convention that the distance 
from 0 to 1 is always one whole.
After defining the whole, 
we can divide into equal parts like this.
Where is one-fourth on the number line?
The point here, must be one-fourth.
Yes, and we know it's one-fourth because it is one-fourth the distance from 0 to 1.
Number lines are particularly useful for representing mixed numbers or improper fractions.
They can also be used to relate
fractions and decimals.
Number lines are a versatile classroom model,
but to develop a deep understanding of fractions
be sure that your language matches
the attribute of distance.
