The following is the test of Xiaoming's heartbeat before and after exercise: after exercise, he beats 140 beats per minute, which is 65 beats more than before exercise. How many beats per minute does Xiao Ming's heart beat before exercising?
下面小明运动前后心跳的测试情况：运动后每分钟跳140下，比运动前多65下．小明运动前每分钟心跳多少下？
<gadget id="calculator">140 - 65</gadget>
<output>75</output>

<result>75</result>