JJ should leave $1.20 as the tip.
The total of JJ’s meal was $8.
$5.50 + $2.50 = $8.00
To find the tip, you need to know what 15% of $8 is. That is done by multiplying 15% and the total of JJ’s meal. Change the percent to a decimal by moving the decimal point, two places to the left.
0.15 • $8.00 = $1.2, but more known as $1.20.