Distribute Unifix cubes so that children can create their own measuring devices. When the children are ready to measure, you may wish to give some suggestions, or have some items prepared that you already know the measurements of.
Have the children connect a line of Unifix cubes together to create their own measuring sticks. Allow the children to decide how many cubes are used in their measuring sticks.
Using their new measuring sticks, have the children measure different items in the classroom. Some objects to measure may include the length of a table, and even other children.
If developmentally appropriate, have the children draw a picture of what was measured and write the numeral beside the picture to indicate how many cube lengths long that item is.
For an optional extra challenge, have the children try to predict how many units long an object is. Then, let them measure and see who came the closest.