Two identical glasses are filled with sugar water. The mass ratio of sugar to water is 1:7 and 1:9 respectively. Now mix these two glasses of sugar water. What is the sugar content of the mixed sugar water?
两个相同的玻璃杯，都装满了糖水，糖与水的质量比分别是1：7和1：9，现将这两杯糖水混合，混合后糖水的含糖率是多少．
<gadget id="calculator">7 + 1</gadget>
<output>8</output>

<gadget id="calculator">1 / 8</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">9 + 1</gadget>
<output>10</output>

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

<gadget id="calculator">(1/8) + (1/10)</gadget>
<output>9/40 = around 0.225</output>

<gadget id="calculator">(9/40) / 2</gadget>
<output>9/80 = around 0.1125</output>

<gadget id="calculator">100 / 100</gadget>
<output>1</output>

<gadget id="calculator">(9/80) * 1</gadget>
<output>9/80 = around 0.1125</output>

<result>9/80 = around 0.1125</result>