The minimum temperature in A and B on the same day is 4°C and 7°C respectively, what is the difference in the minimum temperature of the two places on this day?
甲、乙两地同天最低气温分别是4℃和7℃，这天两地最低气温相差多少℃．
<gadget id="calculator">7 - 4</gadget>
<output>3</output>

<result>3</result>