(3 x 10^3) + (2 x 10^2) + (4 x 10) =  Answers.
A) 302400 B) 32400 C) 30240 D) 3240 E) 324
When you multiply a number by 10 you just add a zero   =&gt; 3 x 10^3 =&gt; add 3 zeros =&gt; 3 x 10^3 = 3000   =&gt;2 x 10^2 = 200   =&gt; 4 x 10 = 40   =&gt;3 x 10^3 + 2 x 10^2 + 4 x 10 = 3000 + 200 + 40= 
<gadget id="calculator">3000 + 200 + 40</gadget>
<output>3_240</output>
3240=&gt; answer is 3240 ( 3240)
<result>D</result>
(3 x 10^3) + (2 x 10^2) + (4 x 10) =