Assuming 10 digits, 0,1,2,3,4,5,6,7,8,9 are in play, digits are not repeated and order of appearance of 4 digits and 5 digits is not of importance, the following applies.
Number of combinations of 4 digits from among 10 digits = 10!/(6!)(4!) = 210 which = the number of ways to select 4 digits in any order from among 10 digits.
You select one of the 4 digit outcomes and your probability of success = 1/210 = 0.0047619047…~ 0.48%. Odds of success are 1:209.
Number of combinations of 5 digits from among 10 digits = 10!/(5!)(5!) = 252 which = the number of ways to select 5 digits in any order from among 10 digits.
You select one of the 5 digit outcomes and your probability of success = 1/252 = 0.00396825…~ .397%. Odds of success are 1:251.
Edit: The forgoing has been altered because it had a fault regarding combinations vs permutations which has been corrected.
The only way to increase your chance of success is to purchase more lottery tickets, using different digits of course!