A cow produces 25 kilograms of milk per day. How many kilograms of milk will be produced by 4 cows in August?
一头奶牛每天产奶25千克，4头奶牛，八月份共产奶多少千克？
<gadget id="calculator">25 * 4 * 31</gadget>
<output>3_100</output>

<result>3_100</result>