how to do upper/lower rounding in math

[arctushar]

how to do upper/lower rounding in math

example
A number is 124.3

now I want get value 124 and 125 from this. is there any command? for that.
clearly

function(y.x) = y+1
function(y.x)=y
what those functions are please help me

[devinemke]

[man]round[/man]
[man]ceil[/man]
[man]floor[/man]