Put it into the calc as
(9*11)^9
$${\left({\mathtt{9}}{\mathtt{\,\times\,}}{\mathtt{11}}\right)}^{{\mathtt{9}}} = {\mathtt{913\,517\,247\,483\,640\,899}}$$
now put 1 digit in front of the point
The point has moved from the very end to between the 9 and the 1. That is 17 places
It is a big number so it is a positive power
$$9.13517247483640899 \times 10^{17}$$
Can either go 9x9x9x9x9x9x9x9x9*11x11x11x11x11x11x11x11x11 or
(99)to the power of 9
use calculator
Put it into the calc as
(9*11)^9
$${\left({\mathtt{9}}{\mathtt{\,\times\,}}{\mathtt{11}}\right)}^{{\mathtt{9}}} = {\mathtt{913\,517\,247\,483\,640\,899}}$$
now put 1 digit in front of the point
The point has moved from the very end to between the 9 and the 1. That is 17 places
It is a big number so it is a positive power
$$9.13517247483640899 \times 10^{17}$$