There are 3 math teachers and 6 Chinese teachers in the third grade of the school. If every two teachers make a phone call, how many phone calls will be made in total?
学校三年级有3位数学老师和6位语文老师，如果每两位老师之间通一次电话，一共要通多少次电话？
<gadget id="calculator">3 + 6</gadget>
<output>9</output>

<gadget id="calculator">6 - 1</gadget>
<output>5</output>

<gadget id="calculator">3 + 5</gadget>
<output>8</output>

<gadget id="calculator">8 / 2</gadget>
<output>4</output>

<gadget id="calculator">9 * 4</gadget>
<output>36</output>

<result>36</result>