Units

Attach a measurement unit to every quantity you write down, and use the same one throughout. Naked numbers hide what they measure; a unit makes scale visible and turns a mismatched calculation into a mistake you can see immediately.

Attach a measurement unit to every quantity you write down, and use the same one throughout. Naked numbers hide what they measure; a unit makes scale visible and turns a mismatched calculation into a mistake you can see immediately.

Example

In your chemistry notes, [A] is never just 0.40, it is 0.40 mol/L, and the rate is 0.012 mol/L per second. When a homework answer comes out in mol/L instead of mol/L per second, you know you dropped a step.