1-4: Units of Measurement and Metric Conversions By Ms. Pacheco

Measurements Require a NUMBER and a UNIT International System of Units (SI): agreed upon back in the 1960s as standard units that scientists around the world would use. They agreed that the metric system would be used. Why? All of the metric units are based on units of 10, which makes them easier to use.

Length Distance from one point to another SI unit: meter (m) This is about the distance between a doorknob and the floor

Mass and Weight Mass: amount of matter in an object Weight: the force of attraction of gravity on an object Which is constant, no matter where you are? Mass SI unit: kilogram (kg) One kg = 2.2 lbs

Derived Units Occurs when base units are combined. How do you calculate the area of, say, a rectangle? Length x width Which might give units of m x m, or… m2 m2 would be a derived unit

Volume The amount of space an object occupies It is also a derived unit How would you calculate the volume of a washing machine box? Length x width x height SI unit cubic meter (m3); more commonly used is the liter (L) or the cubic centimeter (cc or cm3) 1 cc = 1mL