The Olympic Games aroused everyone's enthusiasm for sports. The school had to buy the same football for each of the five classes of the third grade. Each class was 21 yuan. How much did it cost in total?
奥运会掀起了大家的运动热情，学校要给三年级的5个班每班买一个同样的足球，每个21元，一共要用多少钱？
<gadget id="calculator">21 * 5</gadget>
<output>105</output>

<result>105</result>