Asupercomputer can do 136.8 terra calculations per second. how many calculations can it do in a microsecond

"terra..." as a prefix means  10¹² ,
so the unit speed of this computer is 

                                             136.8 x 10¹² calcs/sec.

"micro..." as a prefix means  10⁻⁶ ,
so in that amount of time, the computer can do

         (136.8 x 10¹² calc/sec) x (1 x 10⁻⁶ sec)  =  136.8 x 10⁶  calcs.

That's ...

... 136.8 mega-calcs

... 0.1368 giga-calcs

... 136,800 kilo-calcs

... 136,800,000 calculations