To build a road with a length of 6.4 kilometers, an average of 1.2 kilometers was built every day in the first 3 days, and the remaining 1.4 kilometers was built every day, and it will take several days to complete.
修筑一条长6.4千米的公路，前3天平均每天修筑1.2千米，剩下的每天修筑1.4千米，还要几天才能完成．
<gadget id="calculator">1.2 * 3</gadget>
<output>3.6</output>

<gadget id="calculator">6.4 - 3.6</gadget>
<output>2.8</output>

<gadget id="calculator">2.8 / 1.4</gadget>
<output>2</output>

<result>2</result>