Multiple numbers calculator
There are some places where you can dictionaries instead of if/elif/else statements, I will analyze one here:

if(act=='+'):
    total=num1+num2
elif(act=='-'):
    total=num1-num2
elif(act=='*'):
    total=num1*num2
elif(act=='/'):
    total=num1/num2
else:
    print("input not recognized")


Is often re-written as a dictionary. So, you could create a dictionary called OPS and write:

import operator

OPS = {
    '+' : operator.add,
    '-' : operator.sub,
    ...
}
ERROR = lambda arg1, arg2: print("input not recognized")


You can then you can do:

def calculate(num1, num2, act):
    return OPS.get(act, ERROR)(num1, num2)


This tries getting the particular key which is a function. It then calls it. If the operator is not found, it defaults to the ERROR.