How many tons is 40% of 0.7 tons?
0.7吨的40%是多少吨．
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">0.7 * (2/5)</gadget>
<output>0.28</output>

<result>0.28</result>