...this:
Original number=1234
Those numbers must be multiply with the formula "7,3,1" from right to left. So in this case we must do the multiply 7*4, 3*3, 1*2, 7*1. We get numbers 28,9,2,7. Then we take the SUM 28+9+2+7 and we get number 46. Then we take the nearest FULL TEN upward, which is...