Grandpa Li has a rectangular vegetable field with an area of 450 square meters and a width of 9 meters. If the length remains the same and the width is increased by 3 times, how much will the area of the vegetable field expand? (calculated in two ways)
李爷爷有一块面积为450平方米的长方形菜地，宽9米．如果长不变，宽扩大3倍后，菜地面积扩大多少？(用两种方法计算)
<gadget id="calculator">450 * 3</gadget>
<output>1_350</output>

<gadget id="calculator">1_350 - 450</gadget>
<output>900</output>

<result>900</result>