Unable to convert degree to number in LatitudeLongitude and "City" Entity

Question

I am trying to convert degree to number for some mathematical transformation. Taking London as an example, the following codes can convert the degree into a number without any problems:

Codes that give numbers {51.5,-0.11} and {0.8988,-0.0019} as output:

{51.5°,-0.12°} /Degree
{51.5°,-0.12°} /. GeoPosition -> Identity

However, I want to use London as the input. In fact, if I input

LatitudeLongitude[Entity["City",{"London", "GreaterLondon", "UnitedKingdom"}]]

I can get {51.5°,-0.12°} without a problem.

The problem is, when I combine the two, the result fails to convert into number. It is still in degrees.

Codes that still give degree as output:

LatitudeLongitude[Entity["City",{"London", "GreaterLondon", "UnitedKingdom"}]]/Degree
LatitudeLongitude[Entity["City",{"London", "GreaterLondon", "UnitedKingdom"}]]/. GeoPosition -> Identity 

How can I convert that into degrees?

Answer 1

The output of LatitudeLongitude is a List of Quantitys:

pos = LatitudeLongitude[Entity["City", {"London", "GreaterLondon", "UnitedKingdom"}]]

FullForm@pos

List[Quantity[51.5`,"AngularDegrees"],Quantity[-0.1166667`,"AngularDegrees"]]

This would suggest to use UnitConvert:

UnitConvert[pos, "Radians"]

{0.898845rad,-0.00203622rad}

which again is a List of Quantitys:

FullForm@%

List[Quantity[0.8988445647770799`,"Radians"],Quantity[-0.0020362180424364686`,"Radians"]]

One could extract the numbers with [[All, 1]]. However, this whole line of reasoning leads to overcomplication of the procedure, as the straighforward approach is

Normal@pos

{0.898845, -0.00203622}