Natural numbers less than 100. What is the average of all numbers that are multiples of 3?
100以内的自然数中．所有是3的倍数的数的平均数是多少．
<gadget id="calculator">0 + 99</gadget>
<output>99</output>

<gadget id="calculator">34 / 2</gadget>
<output>17</output>

<gadget id="calculator">99 * 17</gadget>
<output>1_683</output>

<gadget id="calculator">1_683 / 34</gadget>
<output>99/2 = around 49.5</output>

<result>99/2 = around 49.5</result>