Simon wanted to buy flowers that his mom could plant for Mother's Day.  The garden center was offering 10% off all purchases.  He bought 5 pansies at $2.50 each, one hydrangea that cost $12.50 and 5 petunias that cost $1.00 each.  If he paid with a $50 bill, how much change would Simon receive back from his purchase?
5 pansies at $2.50 each is 5*2.50 = $
<gadget id="calculator">5*2.5</gadget>
<output>12.5</output>
12.50
5 petunias at $1.00 each 5*1 = $
<gadget id="calculator">5*1</gadget>
<output>5</output>
5.00.
All total he spends 12.50+12.50+5.00 = $
<gadget id="calculator">12.50+12.50+5.00</gadget>
<output>30</output>
30.00.
The sale is 10% off so 30*.10 = $
<gadget id="calculator">30*.10</gadget>
<output>3</output>
3.00.
The purchase total now comes to 30-3 = $
<gadget id="calculator">30-3</gadget>
<output>27</output>
27.00.
He pays with a $50 bill so 50-27 = $
<gadget id="calculator">50-27</gadget>
<output>23</output>
23.00.

<result>23</result>