Answer:
I'm assuming that you mean "Cubic Unit". I will use inches in this example, but this will work with other units as well.
Let's say that the volume of a figure was 124.86 cubic inches.
Rounding to the nearest cubic inch is the same thing as rounding to the nearest whole number.
Locate the 'ones' place:
124.86
Check next door:
124.<u>8</u>6
If the next door number is greater than or equal to 5, then we round up. If it's less than 5, we round down.
8 is greater then 5. Therefore, we would round up.
So, 124.86 cubic inches to the nearest cubic inch is 125 in³.
124.86in³ ≈ 125in³