This error message occurs if the compiler finds the beginning of a scale factor (an 'E' or 'e' character) in a number, but no digits follow it.

program Produce;
const
  SpeedOfLight = 3.0E 8;    (*<-- Error message here*)
begin
end.

In the example, we put a space after '3.0E' - now for the compiler the number ends here, and it is incomplete.

program Solve;
const
  SpeedOfLight = 3.0E+8;
begin
end.

We could have just deleted the blank, but we put in a '+' sign because it looks nicer.