Xiaohong's height is 120 cm, and her mother's height is 170 cm. How many centimeters does Xiaohong need to grow to be as tall as her mother?
小红的身高是120厘米，妈妈的身高是170厘米．小红再长多少厘米才和妈妈一样高？
<gadget id="calculator">170 - 120</gadget>
<output>50</output>

<result>50</result>