The Nanmo Silk Reeling Mill used 23.02 tons of coal in the previous year, and saved 0.78 tons of coal last year compared to the previous year. This year, it is estimated that it will save 1.2 tons of coal compared with the previous year. How many tons of coal is estimated to be used this year?
南莫缫丝厂前年用煤23.02吨，去年比前年节约用煤0.78吨，今年估计要比前年节约用煤1.2吨，今年估计用煤多少吨？
<gadget id="calculator">23.02 - 1.2</gadget>
<output>21.82</output>

<result>21.82</result>