A mother goes shopping. She buys cocoa at $4.20, laundry at $9.45 and a package of pasta at $1.35. She pays $20. How much change does the cashier give back?
The total shopping cost is $4.2 + $9.45 + $1.35 = $
<gadget id="calculator">4.2+9.45+1.35</gadget>
<output>15</output>
15.
The cashier gives back $20 - 1$5 = $
<gadget id="calculator">20-15</gadget>
<output>5</output>
5.

<result>5</result>