Have students use common classroom manipulatives to compare lengths of different lines. *Students will need a handful of unifex cubes and 1's cubes to assist them in this activity.*
Students will make an estimation of the line's length in both 1's cubes and unisex cubes. They will then use the tools to find the actual "measurement".
I use this activity during our BUILD time, for a "U: Using Manipulatives" activity.