##10^7##
##10^0## = 1 ##10^1## = 10 ##10^2## = 100 ##10^3## = 1000 ##10^4## = 10000 ##10^5## = 100000 ##10^6## = 1000000
Do you see a pattern? 10 to the power of how many zeros there are.
So for ##10^7## we need to write 1 and then 7 zeros behind it
##10^7## = 10000000