Water is composed of hydrogen and oxygen in a mass ratio of 1:8. How many kg of hydrogen is contained in 3.6 kg of water?
水是由氢和氧按1：8的质量比化合而成的．3.6kg的水含有氢多少kg．
<gadget id="calculator">1 + 8</gadget>
<output>9</output>

<gadget id="calculator">1 / 9</gadget>
<output>1/9 = around 0.111111</output>

<gadget id="calculator">3.6 * (1/9)</gadget>
<output>0.4</output>

<result>0.4</result>