The fifth grade carried out tree planting activities, and the survival rate of tree planting was 98%. Among them, Class 5 1 planted 160 trees, and Class 5 2 planted 190 trees. How many trees did not live in their tree planting activities?
五年级开展植树活动，植树成活率为98%，其中五1班植树160棵，五2班植树190棵，他们的植树活动有多少棵树没有活？
<gadget id="calculator">160 + 190</gadget>
<output>350</output>

<gadget id="calculator">98 / 100</gadget>
<output>49/50 = around 0.98</output>

<gadget id="calculator">350 * (49/50)</gadget>
<output>343</output>

<gadget id="calculator">350 - 343</gadget>
<output>7</output>

<result>7</result>