Estimate a 15% tip on a dinner bill of $67.42 by first rounding the bill amount to the nearest ten dollars.

$10.50 is the tip on a dinner bill.

Step-by-step explanation:

The first step is to round off $67.42. It is closer to 70 than 60, therefore it is 70.

Secondly, 10% of 70 is 7.

5% of 7 is 3.5.

*Notice that 10% and 5% equals 15%.

Add 7 + 3.5 = 10.5 or $10.50