Define a*b=aa/b+b, then 4*5=how much
定义a*b=a-a/b+b，则4*5=多少
<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">4 - (4/5)</gadget>
<output>16/5 = around 3.2</output>

<gadget id="calculator">(16/5) + 5</gadget>
<output>41/5 = around 8.2</output>

<result>41/5 = around 8.2</result>