One day, as I was holding up the branch that had fallen from our tree, several of the children called out, *“It’s bigger than you!”* I asked them how we could find out how big the branch is. Although the children know the word “measure” it’s always interesting to watch their understanding of this concept develop. When they said they could “measure” it, I asked them how they would do so. One student said he needed a string with some numbers on it. Another said *“with units.”* This prompted an interesting discussion on what a unit actually is. Measuring the branch became an interesting exploration for a group of children. Some asked for string. Some walked along the branch and counted as they pointed to parts of it. One of the children used her finger to measure the branch.

I put out some number cards and a measuring tape *(a.k.a.; the string with numbers.)* Two of the SKs explored the string while one of the JKs used the number cards. She laid them out and accurately counted how many “cards long” the branch was. The numbers however, were all out of sequence. I was very tempted to prompt her to put them in the correct order, but I decided to be patient and see what would happen. Within a few minutes, an SK friend came over and said, *“The numbers are all mixed up,”* and she helped her JK friend put them in order. It was very powerful to watch them learn from each other. When she was done, she said there were 14. *“14 what?”* I asked. She thought for a bit and said, *“Units?” *I still was not sure that she understood the meaning of unit, but further exploration would reveal the children’s learning and understanding of this concept. She then decided to use some linking cubes to measure the branch. When I asked if her measurement would be the same she said,* “No, because these are smaller. These are 14 (counts the cubes). We need more! Maybe we can use something bigger!” *

Over the last few days, their understanding of a “unit” continues to develop. Here are a few of the ways the children explored using different units to measure the branch:

This is such a powerful demonstration of how important exposure to non-standard units is for children but more importantly the knowledge that children already have.