The longest river in my country - the Yangtze River has a total length of 6380km, and the Yellow River is 278km shorter than that of the Yangtze River (9/10). How long is the Yellow River in kilometers?
我国第一长河--长江全长6380km，黄河比长江的(9/10)要短278km．黄河全长多少千米？
<gadget id="calculator">9 / 10</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">6_380 * (9/10)</gadget>
<output>5_742</output>

<gadget id="calculator">5_742 - 278</gadget>
<output>5_464</output>

<result>5_464</result>