General Engineering Introduction/Units Dimensions
Before science/engineering, confusion existed. Different substances were measured different ways. Chickens were counted differently than snakes. Height was measured differently than horizontal distance on the ground. Different languages added confusion. The confusion shown on the Camp Nelson sign occurred everywhere rather than being a joke. Today a number is assigned to everything. Rule: Don't add numbers unless they have the same units.
Units are involved in every engineering and science class. Don't write a number down without the units. Don't plug into a formula without first checking if it makes sense by plugging in units. Unit mistakes lower respect. Unit problems can cripple an engineering career.
If you know the dimensions of units, you can ace most physics tests without memorizing formulas. Please explore these two pages thoroughly: