Purchaser Xiao Li has purchased two types of steel pipes, A and B, from the same company twice. The total number of A-type steel pipes purchased twice is equal to that of B-type steel pipes. The number of A-type steel pipes purchased for the first time is equal to the number The number of B-type steel pipes is also equal, but the second time is 50% more than the first time. It is known that Xiaoli bought 320 A-type steel pipes for the first time, and the price of A-type steel pipes is twice that of B-type steel pipes ． How many B-shaped steel pipes did Xiao Li buy for the first time?
采购员小李先后两次购买同一家公司的A、B两种型号的钢管，两次购买的A型钢管与B型钢管总数相等，第一次购买的A型钢管数与第二次购买的B型钢管数也相等，但第二次比第一次多用了50%的钱，已知小李第一次购买了320根A型钢管，A型钢管的价格是的B型钢管的2倍．小李第一次购买B型钢管多少根？
<gadget id="calculator">2 * 320</gadget>
<output>640</output>

<gadget id="calculator">50 / 100</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">2 * 320 * (1/2)</gadget>
<output>320</output>

<gadget id="calculator">320 - 320</gadget>
<output>0</output>

<gadget id="calculator">640 + 0</gadget>
<output>640</output>

<gadget id="calculator">2 - 1 - (1/2)</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">640 / (1/2)</gadget>
<output>1_280</output>

<result>1_280</result>