Final answer:
The smallest unit on the rulers we worked with in class yesterday is usually the millimeter (mm).
Step-by-step explanation:
In class yesterday, we worked with rulers to measure objects. The smallest unit on the rulers is usually the millimeter (mm). A millimeter is a tiny unit of measurement that is smaller than a centimeter and an inch. It is represented by the smallest divisions on the ruler. For example, if you measure an object using a ruler and the object's length falls between two consecutive millimeter marks, you can estimate the length to the nearest millimeter.