Hannah went to the mall with $100 to spend at three stores for school. First, she walked into Abercrombie and saw an outfit that was marked 50% off. The original price was $40. To get to the sale price amount, Hannah multiplied 0.5 times $40 and came up with $20 as the sale price. She paid and moved on to the next store with $80 which was 80% of her beginning amount.

Next, Hannah took her remaining $80 (80%) to Francesca's. She saw a dress and a cute necklace that were 1/3 off the original price. The original price of the dress was $60, and the necklace was $21. She divided each price by three to get the discount amount, which was $20 off the dress and $7 off the necklace. She paid the difference, which was $40 for the dress and $14 for the necklace and moved to the final store.

$60/3=$20 discount. $60-$20=$40 sales price.

$21/3=$7 discount. $21-$7=$14 sales price.

$40+$14=$54. $54+$20=$74. $100-$74=$26 left to spend. 26/100=13/50 in simplest form.

Lastly, Hannah took her $26 (13/50 left) and went to the third store Lush. She found 2 bath bombs and 1 bubble bar. The bath bombs were $4.12 each and the bubble bar was $7.34. Hannah multiplied $4.12*2 to get to the total cost of the bath bombs ($8.24). She added $7.34 from the bubble bar which totals $15.58.

Hannah then subtracts $15.58 from 13/50 ($26) which equals to $10.42 and uses it for later.