The water contained in the human body accounts for about 7/10 of the body weight. Xiao Ming's weight is about 40 kg. How many kg of water does Xiao Ming have in his body?
人体含有的水分约占体重的(7/10)，小明的体重大约是40千克，小明身体内的水分约有多少千克？
<gadget id="calculator">7 / 10</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">40 * (7/10)</gadget>
<output>28</output>

<result>28</result>