A scale factor is a contracting scale such that x < 1, where x is the scale factor.
For example, if the scale factor x is less than 1, then it must be decreasing in size, and thus be contracting in size.
But, if the scale factor is greater than 1, then it is expanding in size and increasing.
1) -5 is expanding. It is greater than one.
2) -1/4 is contracting. It is less than one.
3) 3.5 is expanding. It is greater than one.
4) 6/7 is contracting. It is less than one.
