On Sunday, Xiaoxiao asked her father for some money to go to the bookstore, and spent 80 yuan, but only used what her father gave her (4/5), how much did her father give her.
星期日，笑笑向爸爸要了一些钱去书城，用去80元，只是用去爸爸给的(4/5)，爸爸给了她多少元．
<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">80 / (4/5)</gadget>
<output>100</output>

<result>100</result>