QM formula solution required for LOG base 10.

Hi Gurus,

Hope you can point me in the right direction on the below?

I’m trying to convert an excel “log10” formula into a SAP QM formula equivalent, in the task list characteristic formula field. 

Although LOG to base ‘e’ is possible, I cannot get LOG to base ‘10’ to calculate for me!  For example,

Excel formula is:

=LOG(8528.78)  …….answer= 3.93

SAP suggested formula:

LOG10(8528.78), SAP error “Variable LOG10 in items 5 and 6 cannot be identified”

How can I solve this?

Many Thanks