A possible way:
We can start from a problem. How can we write a program which gives
you a string with all the digits from 1 to 9?
s = "1"
for i in range(2,10):
s = s + str(i)
And if we want to change it to start from 3?
s = "3"
for i in range(4,10):
s = s + str(i)
We can see that we need to change two places in our code. For this,
people invented the empty string. We can add it to a string, and
nothing happens! What's its length? 0!
s = ""
for i in range(1, 10):
s = s + str(i)
Do you think it might work?
Noam
