The school buys prizes for outstanding students. I originally planned to buy diaries with a unit price of 1.8 yuan each, but the diaries I bought later cost 0.6 yuan each. I originally planned to buy 80 copies, but how many copies can I only buy now?
学校为优秀学生买奖品．原计划买单价每本1.8元的日记本，后来买的日记本每本贵0.6元．原计划买80本的钱，现在只能买几本？
<gadget id="calculator">1.8 + 0.6</gadget>
<output>2.4</output>

<gadget id="calculator">80 / 2.4</gadget>
<output>33.333333</output>

<gadget id="calculator">1.8 * 33.333333</gadget>
<output>59.999999</output>

<result>59.999999</result>