Question

What is the sum of 4.2 × 105 and 5.3 × 105?

Answer 1

4.2 times 105 is 441 and 5.3 times 105 is 556.5.
441 plus 556.5 is 997.5
So the answer is 997.5

Answer 2

Hey there!

So, first we would do a first part if this problem.

$4.2*105$ 

This would equal . . . .

$\boxed{\boxed{441}}$
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Then we would do the second part of the problem.

$5.3*105$

This would equal . . . .

$\boxed{\boxed{556.5}}$

(By adding both (441) and also (556.5)

This would equal . . . 
                                                   
 $\boxed{\boxed{\boxed{997.5}}}$

Hope this helps.
~Jurgen