A bottle of oil weighs 600 grams in total. Half of the oil is eaten, and the bottle is weighed together. There are 450 grams left. How many grams of oil are in the bottle?
1瓶油连瓶共重600克，吃去一半的油，连瓶一起称，还剩450克，瓶里原来有油多少克．
<gadget id="calculator">600 - 450</gadget>
<output>150</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">150 / (1/2)</gadget>
<output>300</output>

<result>300</result>