16 cows eat 240 kg of grass a day. According to this calculation, Xiaosheng's family raised 9 such cows, how many kilograms of grass would they have to eat a day?
16头奶牛一天要吃草240千克．照这样算，小生家养了9头这样的奶牛，一天要吃草多少千克？
<gadget id="calculator">240 / 16</gadget>
<output>15</output>

<gadget id="calculator">15 * 9</gadget>
<output>135</output>

<result>135</result>