What is the sum of all multiples of 5 in the 100 numbers from 1 to 100?
在1--100这100个数中所有5的倍数之和是多少．
<gadget id="calculator">5 + 100</gadget>
<output>105</output>

<gadget id="calculator">20 / 2</gadget>
<output>10</output>

<gadget id="calculator">105 * 10</gadget>
<output>1_050</output>

<result>1_050</result>