If (1/7) of the number of people in class A is transferred to class B, the number of people in the two classes is equal. It turns out that the number of people in Class A is the number of Class B.
如果把甲班人数的(1/7)调入乙班，两班人数相等．原来甲班人数是乙班的多少．
<gadget id="calculator">1 / 7</gadget>
<output>1/7 = around 0.142857</output>

<gadget id="calculator">(1/7) * 2</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">1 - (2/7)</gadget>
<output>5/7 = around 0.714286</output>

<gadget id="calculator">1 / (5/7)</gadget>
<output>7/5 = around 1.4</output>

<result>7/5 = around 1.4</result>