“just putting value in the gate calculator always gives the correct result??”
No, for this question, it would work but not for all the similar questions. Mod is defined for integers and if your calculator shows some numbers in the form of “E” as @Abhrajyoti00 has mentioned, it means that number is written in power of 10 with some decimal number and so we can’t get the exact result.
Here, you can get the integer value for $3^{32},$ So you can get the correct answer on your gate calculator.
If the number is big and still you have to use your gate calculator without any error then you can use the “repeating squaring” method.
For example, if the question is $3^{128} \mod 80$ then your gate calculator would not work but still you can use the gate calculator as:
$3^{128} \mod 80 = (3^{64} \mod 80 \times 3^{64} \mod 80) \mod 80$
$= ((3^{32} \mod 80 \times 3^{32} \mod 80) \mod 80 \times (3^{32} \mod 80 \times 3^{32} \mod 80)\mod 80 ) \mod 80$
Now, using gate calculator, $3^{32} \mod 80 = 1$
And So, your answer should be $1.$