(2/5) of number A is equal to (1/5) of number B, how much less number A is than number B.
甲数的(2/5)与乙数的(1/5)相等，甲数比乙数少多少．
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(1/5) / 5</gadget>
<output>1/25 = around 0.04</output>

<gadget id="calculator">(1/5) / (1/25)</gadget>
<output>5</output>

<gadget id="calculator">5 / 2</gadget>
<output>5/2 = around 2.5</output>

<gadget id="calculator">5 - (5/2)</gadget>
<output>5/2 = around 2.5</output>

<gadget id="calculator">(5/2) / 5</gadget>
<output>1/2 = around 0.5</output>

<result>1/2 = around 0.5</result>