The method is same like simple Snake and Ladder.
Take a square board [ prefer board of 10 * 10 inches ]
Make grid of 10 by 10 on it.
Make seven snakes and seven ladders on it.
Dont write natural numbers that is 1,2,3,4,5.....
Write fractions i.e. 1/1,2/1 ec. [ actually it is same just write 1 as denominator.]
And your snake and lader game is ready to play...

I hope dis wil help u