Gina is considered a bad tipper because she tipped 5%. If good tippers tip at least 20%, how many more cents than normal would Gina have to tip on a bill of $26 to be considered a good tipper?
First convert the bill amount to cents: $26 * 100 cents/dollar = 
<gadget id="calculator">26*100</gadget>
<output>2_600</output>
2600 cents.
Then multiply that amount by 5% to find the amount Gina normally tips: 2600 cents * 5% = 
<gadget id="calculator">2600*5*.01</gadget>
<output>130</output>
130 cents.
Then multiply the bill amount by 20% to find the amount of a good tip: 2600 cents * 20% = 
<gadget id="calculator">2600*20*.01</gadget>
<output>520</output>
520 cents.
Then subtract the good tip amount from the bad tip amount to find how much more Gina needs to tip: 520 cents - 130 cents = 
<gadget id="calculator">520-130</gadget>
<output>390</output>
390 cents.

<result>390</result>