This comes from the Common Core
Develop understanding of fractions as numbers.
2. Understand a fraction as a number on the number line; represent
fractions on a number line diagram.
a. Represent a fraction 1/b on a number line diagram by defining the
interval from 0 to 1 as the whole and partitioning it into b equal
parts. Recognize that each part has size 1/b and that the endpoint
of the part based at 0 locates the number 1/b on the number line.
b. Represent a fraction a/b on a number line diagram by marking off
a lengths 1/b from 0. …….
….but how do you do it ?????
The mystery is solved…….
Here is the line, with 0 and 1 marked. /You chose it already !
Here is a numbered line, any size, equally spaced, at intervals of one unit.
It only has to start from zero.
Now construct the line from point 5 to the “fraction” line at point 1, and a parallel line from point 1 on the numbered line.
The point of intersection of the parallel line and the “fraction” line is then 1/5 of the distance from 0 to 1 on the “fraction” line.
1/5, 2/5, 3/5, 4/5 and 1 are equally spaced on the fraction line.
L cannot be moved in the static picture.