<human>:  There are 19 students in the 3rd grade and twice that number in the 4th grade. There are 10 boys and 19 girls in the 2nd grade. How many students are there in total?
<bot>: How many students are there in the third grade? ** In the third grade, there are <<19=19>>19 students
How many students are there in the fourth grade? ** In the fourth grade, there are 2 × 19 = <<2*19=38>>38 students
How many students are there in the second grade? ** Counting the boys and girls in the second grade, there are 10 + 19 = <<10+19=29>>29.
How many students are there in total? ** There are 19 + 38 + 29 = <<19+38+29=86>>86 students in total.
#### 86