780
780
780
780.00
780
780
The number 780 is already rounded to the nearest tenth.
780
If we round $776 to the nearest $10, that is $780. Note that you only need to increase $776 by $4 to get to $780, but you would need to decrease it by $6 to get to $770. That's why this amount is nearer to $780 than to $770.
710
Rounded off to the nearest ones is 775, rounded off to the nearest tens is 780, rounded off to the nearest one hundreds is 800.
800
780