The weight of the London Olympic gold medal is the highest in the history of the Summer Olympics. Its mass is 400 grams, which is 155.65 grams heavier than the Beijing Olympic gold medal. How many grams does the Beijing Olympic gold medal weigh?
伦敦奥运会金牌的重量创造了夏季奥运会的历史之最，它的质量是400克，比北京奥运会金牌重155.65克，北京奥运会的金牌重多少克？
<gadget id="calculator">400 - 155.65</gadget>
<output>244.35</output>

<result>244.35</result>