There is an item with a mass of 100 kilograms, first increase its mass (1/10), and then decrease the mass of the subsequent item (1/10), what is the final mass of the item in kilograms?
有质量为100千克的物品，先将它的质量增加(1/10)，再将后来物品的质量减少(1/10)，最后物品的质量是多少千克．
<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">100 * (11/10)</gadget>
<output>110</output>

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

<gadget id="calculator">110 * (9/10)</gadget>
<output>99</output>

<result>99</result>