# What is up with the x! divisions when dealing with cards?

If you're calculating values for poker hand, you often use combinations. For example, if you're calculating the probability of 2 pairs in four cards, you would do $\frac { \frac { 13*{ _{ 4 }{ C }_{ 2 } }*12*{ _{ 4 }{ C }_{ 2 } } }{ 2! } }{ _{ 52 }{ C }_{ 4 } }$. In other words, I do not understand when to put in the $2!$ or $3!$. Would you need to put in the $2!$ when you're calculating the ways you can get a pair above a 7 and then any two other cards below or equal to a 7. Is it $\frac { \frac { { _{ 24 }{ C }_{ 2 } }*7*{ _{ 4 }{ C }_{ 2 } } }{ 2! } }{ _{ 52 }{ C }_{ 4 } }$ or $\frac { { _{ 24 }{ C }_{ 2 } }*7*{ _{ 4 }{ C }_{ 2 } } }{ _{ 52 }{ C }_{ 4 } }$?