I am trying to MULTIPLY - :15 sec * 10. =product((0:15)*10). Os the structure correct?
There is no Err:102, probably you mean Err:502, for which see ebot’s, answer. However, your error is the 0:15 part, you can’t enter times like this in a formula expression, use TIME(0;0;15) instead. Also you don’t need the PRODUCT() function for one argument, specifically you already did the multiplication with the * operator. Your formula should be =TIME(0;0;15)*10
To get something like 0:15 interpreted as a duration at all, it must be text. Then you can apply the function TIMEVALUE() to it. The part in front of the first colon, however, is always taken for the number of hours then, and there is no way to change that by any attributes. Meaning 15 s , you need to write 0:0:15 as text therefore, or better 0:00:15.
Dont start to play it this way if avoidable at all. The colon-notation is specified for TOD (TimeOfDay).
Durations should be given in actual units like 3 h 21 min 33 s. Unfortunately spreadsheets neither supply functions to accept this format for conversion to a numeric standard representation, nor support they a respective number format by default, nor is a conversion of duration values given in the frequently misused colon-format to a correct duration format supported.
If you actually have texts giving durations in a correct format, and you need to calculate with them, this might be a case where using a custom function is justified. For LibO V 6.2 or higher there also is an acceptable solution with standard functions. (Thanks to @erAck.)
You may take a glance into this little demo.