After 2.75 tons of coal from the cafeteria were used up in March, 1.25 tons remained. How many tons of coal did the cafeteria bring in in March? (solution by equation)
食堂三月份运来的煤用去2.75吨后，还剩1.25吨，食堂三月份运来多少吨煤？(用方程解)
<gadget id="calculator">1.25 + 2.75</gadget>
<output>4</output>

<result>4</result>