Dad wants to buy books in an online bookstore, store A will sell them at a 30% discount, and store B will get a discount of 19 yuan for purchases of 69 yuan. If the book that Dad wants to buy is priced at 80 yuan. Which bookstore is cheaper to buy? How much money can you save?
爸爸想在网上书店买书，A店打七折销售，B店满69元减19元．如果爸爸想买的书标价为80元．在哪个书店买更省钱？能省多少钱？
<gadget id="calculator">80 - 19</gadget>
<output>61</output>

<gadget id="calculator">70 / 100</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">80 * (7/10)</gadget>
<output>56</output>

<gadget id="calculator">61 - 56</gadget>
<output>5</output>

<result>5</result>