Question

question #4 reference q.46780 why do we need units in physics? after all, 1+1=2. notice there are no units!

Explanation:

In physics, quantities have physical meaning. Units define what is measured. Without them, values are ambiguous. For example, 1 meter + 1 meter is meaningful, but just 1+1 is abstract math.

Answer:

To define and distinguish physical quantities precisely.