[tex]R=8\Rightarrow O=4 \vee O=9[/tex].
If [tex]O=4\Rightarrow T=2 \vee T=7[/tex].
But none two three-digit numbers starting with 2 give a four digit number as a result when added up, therefore [tex]T=7 \Rightarrow F=1[/tex]
There's [tex]W[/tex] and [tex]U[/tex] left.
[tex]W[/tex] can't be equal to 0, because this would mean also [tex]U=0[/tex] and each letter is supposed to represent a different digit.
[tex]W[/tex] can't be equal 1, because [tex]F=1[/tex].
[tex]W[/tex] can't be equal 2, because [tex]U[/tex] would be equal 4, and already [tex]O=4[/tex]
[tex]W=3[/tex] seems to be a fine digit, because then [tex]U=6[/tex] and 6 hasn't been used yet.
So [tex]FOUR=1468[/tex].
It's possible that there are more solutions (for the rest values of [tex]W[/tex] and for [tex]O=9[/tex], but I don't want to check for them :D
And sorry for my laconic explanation. I suck at this, especially in English :P
