The People's Iron Works planned to smelt 1,800 tons of iron in April; it smelted the original plan (2/5) in the first ten days, and smelted the original plan (9/20) in the middle ten days; how many tons of iron were smelted in the first and middle ten days?
人民炼铁厂四月份计划炼铁1800吨；上旬炼了原计划的(2/5)，中旬炼了原计划的(9/20)；问上、中旬共炼铁多少吨？
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">9 / 20</gadget>
<output>9/20 = around 0.45</output>

<gadget id="calculator">(2/5) + (9/20)</gadget>
<output>17/20 = around 0.85</output>

<gadget id="calculator">1_800 * (17/20)</gadget>
<output>1_530</output>

<result>1_530</result>