Change the size of the answer blanks
Double integral, with a lower limit that is not an answer blank
put the limits of integration after the integral symbol instead of on top (and below) by setting limits=>0:
Fundamental Theorem of Calculus
Summation where the student has to input the summation variable, and the limits of the sum
a sum with answer blanks for the upper and lower limits, and the summation variable is i
a sum with answer blanks for the upper and lower limits, and summation variable is not used.