The number A is 10% less than the number B, and the number B is 10% more than the number C. What fraction of B is A?
甲数比乙数少10%，乙数比丙数多10%，问甲是乙的几分之几？
<gadget id="calculator">10 / 100</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">(1/10) / 1</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">1 * (1/10)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">1 - (1/10)</gadget>
<output>9/10 = around 0.9</output>

<result>9/10 = around 0.9</result>