According to the histogram of frequency distribution, the frequency of students whose data is not between [130, 140] is

(0.005+0.035+0.020+0.0 10)× 10=0.7,

∴ The frequency of students' data between [130, 140] is:

1-0.7=0.3,

The number of students whose grades are within [130, 140] is 0.3× 100 = 30.

So the answer is: 30.