For a newspaper, if you subscribe once a month, there is no discount, and each copy is 10 yuan; if you subscribe once a year, you can get a 10% discount. How much can you save by subscribing to this newspaper every year compared to once a month?
一种报纸，如果一个月一订，没有优惠，每份10元；如果一年一订，可打九折，订阅一份这种报纸，一年一订比一个月一订节省多少元？
<gadget id="calculator">10 * 12</gadget>
<output>120</output>

<gadget id="calculator">90 / 100</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">10 * (9/10) * 12</gadget>
<output>108</output>

<gadget id="calculator">120 - 108</gadget>
<output>12</output>

<result>12</result>