It is important for children to have opportunities to learn more about measurement. They learn through thinking about measurement problems. Knowing about how children tend to think about measurement helps adults to guide children's discovery of the principles of measurement. If children are simply told to measure length in a unit like an inch, they develop very little understanding of the principles of measurement. Children need the opportunity to understand principles about measurement.
Appropriate units Use units of measure appropriate to the thing being measured.
Units that work for measuring the length of your driveway may not work for measuring the length of your notebook. Units used to measure length may not serve well for the measurement of area. Identical units To say that a candy bar is 5 inches long means that every inch is exactly the same. Measurement conventions Standard units like inches exist as the result of discussions and agreements among people about measurement problems. People in his kingdom adopted this as a standard that has been passed on.