Students will interpret the rounding involved in measuring to identify the possible range of a given measurement.

Have students measure the length of a table or desk in the room and record the measurement to the nearest millimeter, for example, 1357 mm.

Discuss how measurements in millimeters can be recorded as 1357 mm or as thousandths of meters, 1.357 m. Note that the measurement was rounded to 1357 mm because it fell somewhere between ½ of a millimeter less than 1357 mm (1356.5 mm) and ½ of a millimeter more than 1357 mm (1357.5 mm).