Estimate a 15% tip on a dinner bill of $32.14 by first rounding the bill amount to the nearest ten dollars.

Rounding $32.14 to the nearest ten dollars results in $30, as $32.14 is below $35. Multiplying $30 by 0.15 (15%) gives us $4.50. The tip is approximately $4.50, and the total is approximately $36.64.