The units were interrelated. Units of one measure, such as length, increased by powers of ten (millimeters, centimeters, decimeters, meters). A liter was the volume of a cube 10 centimeters on a side.

―Units of Length― Barky realizes that the measurement can be made by counting how many 1-centimeter items are needed, and the customer's foot is measured successfully. Transcript ...

The sunflower is 214 cm tall. Calculate the height of the sunflower in metres and millimetres. There are 100 centimetres in a metre. Metres are larger than centimetres so the number of centimetres ...

Units of speed are always a unit of length per unit of time. Different units of length and time may be chosen depending on the situation. This makes it easier to read the measurements. For example ...

An angstrom (Å) is a unit of length equal to 10-10 meters or 0.1 nanometers. It is named after the Swedish physicist Anders Jonas Ångström, who first used it to measure the wavelengths of light. The ...