Answer :

lollol
400 + 70 + 8
Because the 4 is in the hundred's place, the 7 is in the ten's place, and the 8 is in the one's place.
If you pût h above thé 4 wich stands for thé hundreds collum then a t under thé 7 for thé tend collum and you pût a u above thé 8 then you can see it easier

400,70,8