One of the math focuses in our curriculum is an introduction to measurement. The following are some activities I've used in our classroom to introduce measurement concepts.
Full & Empty: To demonstrate the idea of full and empty I put the containers from our balance scale on a tray with corn to pour from container to container. As the students played we would ask from time to time which container was full or empty. We would also challenge them to make one full or empty.
Heavy & Light: We played with our balance scale and sized elephant counters. While students explored we talked about how the scale worked, showing which container was heavy or light. I also encouraged my older students to sort the elephants by color to see which group was the heaviest.
Long & Short:
Play dough mats. I drew a long and short rectangle on a piece of paper and put the paper inside a page protector. I encouraged the students to make the play dough match the lines, to make one piece long and one piece short. Some of the students used scissors to cut the play dough to size.
Measuring with Yarn: This is one of my favorite length activities, although it takes some patience on the students part to wait for everyone to be measured. It might be a good idea to measure everyone with a length of yarn as they come in the door in the morning, but it was fun to watch everyone get measured too.
I cut a length of yarn to match each students height. I wrote their name on a piece of tape and attached the yarn to the wall. After everyone is hanging we compare the different lengths, seeing who is long and who is short!