I am attempting to program a simple Python calculator for experience. However, I am having a syntax issue with the elif statement and an error with the operations (for example, 12 + 13 gives me 1213).

```
def add(a,b):
return a + b
def subtract(a,b):
return a - b
def multiply(a,b):
return a * b
def divide(a,b):
return a/b
print "Enter 1 for addition"
print "Enter 2 for subtraction"
print "Enter 3 for multiplication"
print "Enter 4 for division"
operation = raw_input()
num1 = raw_input("Enter first number")
num2 = raw_input("Enter second number")
if operation == "1":
print num1 + "+" + num2 + "=" + add(num1,num2)
elif operation == "2":
print num1 + "-" + num2 + "=" + subtract(num1,num2)
elif operation == "3":
print (num1) + "*" + (num2) + "=" + (multiply(num1,num2)
elif operation == "4":
print num1 + "/" + num2 + "=" + divide(num1,num2)
```