There is a fraction, add 1 to the denominator, the fraction becomes (1/3), add 3 to the numerator, the fraction becomes 1, what fraction is this fraction?
有一个分数，把分母加上1，这个分数就变为(1/3)，把分子加上3，这个分数就变为1，这个分数是几分之几？
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">(1/3) * 3</gadget>
<output>1</output>

<gadget id="calculator">1 + (1/3)</gadget>
<output>4/3 = around 1.333333</output>

<gadget id="calculator">1 - (1/3)</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">(4/3) / (2/3) / 5</gadget>
<output>2/5 = around 0.4</output>

<result>2/5 = around 0.4</result>