Two barrels of oil weigh 4 kilograms. Now pour 1 kilogram of oil from barrel A into barrel B. At this time, the amount of oil in barrel A is equal to that of barrel B.
两桶油都重4千克，现从甲桶油中倒出1千克到乙桶，这时甲桶油量是乙桶的多少
<gadget id="calculator">4 - 1</gadget>
<output>3</output>

<gadget id="calculator">4 + 1</gadget>
<output>5</output>

<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<result>3/5 = around 0.6</result>