how P6 computes for total float subtotal and why schedule variance is not zero reference to newly created baseline?

Dear PP Members,

1) How does P6 compute for the subtotal of total floats. There is a group consist of 5 activities, 4 activities having total float of 2 days each and 1 activity whose total float = -10days. The group subtotal of total float is -6days.

2) Why schedule variance is not equal to zero reference to a newly created baseline of an "in-progress project''? As far as I know, schedule variance should be zero because the baseline is just the exact copy of the current. Is there a way in P6 to set SV=0?

Thanks in advance.

Merry Christmas!!!

Jerome