During the spring outing, some students in class one went boating. If they rent one more boat, each boat can accommodate exactly 4 people; if they rent one less boat, each boat can accommodate exactly 6 people, how many boats have they rented in total?
在春游活动中，一班的部分同学去划船．如果他们多租一条船，每条船上恰好能坐4人；如果他们少租一条船，每条船上恰好能做6人，他们一共租了几条船？
<gadget id="calculator">4 + 6</gadget>
<output>10</output>

<gadget id="calculator">6 - 4</gadget>
<output>2</output>

<gadget id="calculator">10 / 2</gadget>
<output>5</output>

<result>5</result>