The steps
For ratios, use the same order each time so when an answer is wrong, you know which step to re-check. Ratios shows the whole topic in one place.
Why one line at a time
One move per line when you work through ratios. If you combine two moves on one line and get stuck, you cannot see which move was wrong.
Worked pattern
Example: balance an equation. Add or subtract on both sides, or multiply or divide both sides by the same nonzero number. Write the new equation on the next line each time.
Two ways to write work
One step per line Two steps on one line
Confirm
Core lesson
Related: Ratios. Use the calculator with your own numbers when the example is not close to your case.