lion raised in a zoo weighed 190 kg last year and 220 kg this year. How many kilograms has the lion gained this year compared to last year?
动物园饲养的一头狮子，去年的体重是190千克，今年的体重是220千克．这头狮子今年比去年体重增加了多少千克？
<gadget id="calculator">220 - 190</gadget>
<output>30</output>

<result>30</result>