Answer:
$310
Step-by-step explanation:
The first step is to add the costs of the textbook together :
$68.41 + $105.35 + $72.49 + $59.91 = $306.16
In order to round off to the nearest ten dollars, look at the units figure, if the number is greater or equal to 5, add 1 to the ten figure. If this is not the case, add zero. Replace the unit digit with zero
The unit digit is greater than 6, so 1 is added to the tens digit. The amount becomes $310
