The experimental primary school has to buy a copy of "Science and Technology Expo" for each of the students in the third and fourth grades at a price of 24 yuan. It is known that there are 245 students in the third grade and 255 students in the fourth grade. How much is the total cost for the two grades?
实验小学要为三、四年级的学生每人买一本价格为24元的《科技博览》．已知三年级有245人，四年级有255人，两个年级一共需要多少元？
<gadget id="calculator">245 + 255</gadget>
<output>500</output>

<gadget id="calculator">500 * 24</gadget>
<output>12_000</output>

<result>12_000</result>