A value of type “single” is a single precision floating point number. For the computer, it is 32 bits where one is used for the sign (+ or -), 8 are used for an exponent (power) of 2, and 23 are used for the fractions…

In a brief: single values can be positive or negative, can represent fractions (e.g. 0.25 or 3.75) - and hence are usually the result of division/multiplication operations.

The appropriate casting function is Math.Cast.ToSingle.

An example is

<step>ActionScript.SetProperty("Playbacks.Editor.Times.ChaseFixtureOverlap", Math.Cast.ToSingle(1))</step>

Here, the value 1, albeit a number, is cast to a single value which is 3f80 0000 (hex) resp. 0 01111111 00000000000000000000000 (binary) because the function Playbacks.Editor.Times.ChaseFixtureOverlap needs to be a single.

Single values do not need to be written in quotes. However, due to its nature, you'll probably never write or even see a single value. You just need to know what it is, and how to pass it (most likely by passing another function or property where you make sure it is a single value…)