The heavy machinery factory used to use 9 tons of steel per day. After the technological innovation, it saves 1.8 tons per day. Therefore, how many days can the steel used for 16 days be used now?
重型机器厂原来每天用钢材9吨，技术革新后，每天节约1.8吨，因此原来16天用的钢材，现在可以用几天？
<gadget id="calculator">9 - 1.8</gadget>
<output>7.2</output>

<gadget id="calculator">16 / 7.2</gadget>
<output>2.222222</output>

<gadget id="calculator">9 * 2.222222</gadget>
<output>19.999998</output>

<result>19.999998</result>