A batch of flour, 40% was eaten in the first week, and 500 kg was eaten in the second week, leaving 700 kg. How many kilograms is this batch of flour?
一批面粉，第一周吃去40%，第二周吃去500千克，还剩700千克．这批面粉一共多少千克？
<gadget id="calculator">500 + 700</gadget>
<output>1_200</output>

<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (2/5)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">1_200 / (3/5)</gadget>
<output>2_000</output>

<result>2_000</result>