I would multiply 60 by 3, since its 300+%
60 x 3 = 180
From there I would then add at least half of 60, which is 30
180 + 30 = 210
Since it is 380, I would just add another 20 to the equation to get around :
210 + 20 = 230
This should be a good enough estimate that is close to 380% of 60