Xiao Hao's current weight is 40 kg, which is 1.6 kg more than 12 times that at birth. How many kilograms did he weigh at birth?
小昊现在的体重是40千克，比出生时的12倍还多1.6千克．他出生时的体重是多少千克？
<gadget id="calculator">40 - 1.6</gadget>
<output>38.4</output>

<gadget id="calculator">38.4 / 12</gadget>
<output>3.2</output>

<result>3.2</result>