bound

This is the name given to the least and greatest limit of values and measurements.

For example, if a length of wood is 11 cm to the nearest centimetre, what is the possible range of the length of wood?

Its length must be at least 10.5 cm so that it can be rounded up to 11 cm. But, it must be less than 11.5 cm so that it can be rounded down to 11 cm. The name given to these values is the bound.

Therefore, 10.5 cm is the lower bound and 11.5 cm is the upper bound.