Find the sum of the seix even multiples of 18 starting from 36

six*

Sum= 18 (2 + 4 + 6 + 8 + 10 + 12)=
=18*2(1 +2 + 3 + 4 + 5 + 6)
=36(21)= 36*20 + 36
= 720 + 36= 756

check my math.