12 people from Xinxing Elementary School's "Environmental Guard" team participated in the tree planting activity. The boys planted 3 trees each, and the girls planted 2 trees each, for a total of 32 trees. How many boys are there?
新星小学"环保卫士"小分队12人参加植树活动．男生每人栽了3棵，女生每人栽了2棵，一共栽了32棵．男生有多少人．
<gadget id="calculator">12 * 3</gadget>
<output>36</output>

<gadget id="calculator">36 - 32</gadget>
<output>4</output>

<gadget id="calculator">3 - 2</gadget>
<output>1</output>

<gadget id="calculator">4 / 1</gadget>
<output>4</output>

<gadget id="calculator">12 - 4</gadget>
<output>8</output>

<result>8</result>