Xiao Fang holds two toys and weighs them together, the total weight is 30 kg, and each toy weighs 5 kg. How many kilograms does the cube weigh?
小方抱着两个玩具一起称，共重30千克，每个玩具重5千克．小方体重是多少千克？
<gadget id="calculator">5 * 2</gadget>
<output>10</output>

<gadget id="calculator">30 - 10</gadget>
<output>20</output>

<result>20</result>