The food store bought a batch of bread at a price of 1.6 yuan each, and then sold it at 2.5 yuan each. When there were still 80 breads left unsold, the cost had been fully recovered and a profit of 250 yuan had been obtained. How many pieces of bread are there?
食品店以每只1.6元的价格购进一批面包，然后按照每只2.5元售出，当还剩下80只没售完时，已全部收回了成本，还获得250元的利润，这批面包共多少只？
<gadget id="calculator">1.6 * 80</gadget>
<output>128</output>

<gadget id="calculator">128 + 250</gadget>
<output>378</output>

<gadget id="calculator">2.5 - 1.6</gadget>
<output>0.9</output>

<gadget id="calculator">378 / 0.9</gadget>
<output>420</output>

<gadget id="calculator">420 + 80</gadget>
<output>500</output>

<result>500</result>