A bag of 1 kg of salt is placed on one side of the balance, and 5 apples and 4 bags of monosodium glutamate are placed on the other side. Each bag of monosodium glutamate weighs 100 grams. The balance is just balanced. What is the approximate weight of each apple?
天平的一边放了1袋1千克的盐，另一边放了5个苹果和4袋味精，每袋味精重100克，天平正好平衡，每个苹果大约重多少克．
<gadget id="calculator">1 * 1_000</gadget>
<output>1_000</output>

<gadget id="calculator">4 * 100</gadget>
<output>400</output>

<gadget id="calculator">1_000 - 400</gadget>
<output>600</output>

<gadget id="calculator">600 / 5</gadget>
<output>120</output>

<result>120</result>