Water is composed of hydrogen and oxygen in a mass ratio of 1:8. If the water contains 1800 grams of oxygen. So how many grams of hydrogen are in these waters?
水是由氢和氧按1：8的质量比化合而成的．如果水中含1800克的氧．那么这些水中含氢多少克？
<gadget id="calculator">1 / 8</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">1_800 * (1/8)</gadget>
<output>225</output>

<result>225</result>