Human: 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? Assistant:
5 pansies at $2.50 each is 5*2.50 = $12.50
5 petunias at $1.00 each 5*1 = $5.00
All total he spends 12.50+12.50+5.00 = $30.00
The sale is 10% off so 30*.10 = $3.00
The purchase total now comes to 30-3 = $27.00
He pays with a $50 bill so 50-27 = $23.00