Put
your first number in the
first box. 
Third:
Choose + to add
 to subtract
* to multiply
/ to divide
^ to square or cube
^ will work for square root and cube root if you use a decimal
in the second box

Put your second number in
the second box
(0.5
for square root.
0.33 for cube root)

Fourth:
Answer will appear in
the box above. 