Twice the number of students present in the science class yesterday is 70*2 = <<70*2=140>>140
Ten percent less than twice the number of students present in the class yesterday means there are 10/100*140 = <<10/100*140=14>>14 fewer students than twice the number present yesterday.
The number of students present in the science class today is 140-14 = <<140-14=126>>126
If the total number of registered students for the course who are absent today is 30, a full class of the science course has 126+30 = 156 students.
#### 156