Try a simple estimation game when you are working with children to measure length. Before children arrive for the day, measure several items in your classroom with a standard ruler. Write down the name of the object you measured on one index card, and the length in inches on another index card. As children arrive for the day, pass the cards out to the class. Each student gets one card. Play a game in which the children must pair up, matching the object to its correct measurement. Allow the use of rulers, but also encourage estimation.
In order for children to understand the different types of tools used to measure things as well as the many things human beings measure, try a simple game. List several things that can be measured on the chalkboard or white board. Some examples are the length of a TV show, the distance from home to school, the weight of a box or their own height. Ask children to tell you how they would measure each of these things, as well as the words they would use to describe it to others. For example, children can use a clock to discuss how long a TV show is, and would describe the length in minutes. This will help reinforce the terminology used in different types of measurement.
Collect several different objects from around the classroom, such as paper clips, pencils, a notebook or a piece of paper. Use a balance scale for this game, and challenge children to balance the scale using the school supplies. Explain that when the scale is balanced, the objects on both sides of the scale are equal in weight. Ask children to decide how many pieces of paper equal the same weight as a pencil. Encourage the children to make estimations and then test their hypothesis using the scale.
Split your class into teams of two and give each team a list of several things in the classroom to measure. Provide each team with the tools, such as rulers and scales, to measure each thing on the list. Some ideas for things to include on the list include the length of the chalkboard, the weight of an eraser or the distance from their desk to the water fountain. Give the team that finishes first with the most correct answers a small prize.