Final answer:
To estimate the tip by rounding the bill to the nearest dollar, round $77.04 to $77 and calculate 20% of $77. The approximate amount of the tip is $15.40.
Step-by-step explanation:
To estimate the amount of the tip by rounding the bill to the nearest dollar, you can round $77.04 to $77. Then, calculate 20% of $77 to find the amount of the tip.
To calculate the tip, you can multiply $77 by 20% or 0.2.
Tip = $77 * 0.2 = $15.40
Learn more about estimating tip amount