A certain township wants to build a 1,800-meter-long canal around the mountain. The first phase of the project completed 50% of the total length, and the second phase of the project completed 40% of the total length. How many meters were built in the two phases?
某乡要修一条长1800米的环山水渠，第一期工程修了全长的50%，第二期工程修了全长的40%，两期工程一共修了多少米？
<gadget id="calculator">50 / 100</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(1/2) + (2/5)</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">1_800 * (9/10)</gadget>
<output>1_620</output>

<result>1_620</result>