After the radius of the base of the cylinder increases (1/10), the height remains the same, but the volume increases by how much.
圆柱的底面半径增长(1/10)后，高不变，体积增大多少．
<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">1 + (1/10)</gadget>
<output>11/10 = around 1.1</output>

<gadget id="calculator">(11/10) ** 2</gadget>
<output>121/100 = around 1.21</output>

<gadget id="calculator">(121/100) - 1</gadget>
<output>21/100 = around 0.21</output>

<result>21/100 = around 0.21</result>