A is 10% less than B, which means that the number of A is the number of B.
甲比乙少10%，表示甲数是乙数的多少．
<gadget id="calculator">10 / 100</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>