Creating a macro to change "2 over 7" to fraction form by calling the formula
object:
Select characters to convert
run record macro
click insert - object - formula
The page immediately updates 2 over 7 to fraction form
Then run configure to assign macro to a key sequence (ctrl f)
Retype 2 over 7, select, and press ctrl f - nothing happens
Edit the macro - the last line needs to be uncommented - then it works fine:

rem before editing to correct the problem
sub formula
rem ----------------------------------------------------------------------
rem define variables
dim document   as object
dim dispatcher as object
rem ----------------------------------------------------------------------
rem get access to the document
document   = ThisComponent.CurrentController.Frame
dispatcher = createUnoService("com.sun.star.frame.DispatchHelper")

rem ----------------------------------------------------------------------
rem dispatcher.executeDispatch(document, ".uno:InsertObjectStarMath", "", 0,
Array())


end sub