Calculation: 4.2*26+0.42*640+42=how much.
计算：4.2*26+0.42*640+42=多少．
<gadget id="calculator">4.2 * 26</gadget>
<output>109.2</output>

<gadget id="calculator">0.42 * 640</gadget>
<output>268.8</output>

<gadget id="calculator">109.2 + 268.8 + 42</gadget>
<output>420</output>

<result>420</result>