Which is the best estimate for the product of 3,826.301 × 175.6? A. 8,000,000 B. 800,000 C. 80,000 D. 8,000

Question

Which is the best estimate for the product of 3,826.301 × 175.6?

A.
8,000,000

B.
800,000

C.
80,000

D.
8,000

Answer 1

I suggest rounding up 3,826.301 to 4000, and rounding up 175.6 to 200, which gives a rough estimate of 

 

4000 x 200 = 800,000

 

That agrees with answer (B).  However, the problem did not specify the number of significant digits required in the estimate.  The answer of 800,000 is good to only 1 significant figure.

 

Answer 2

4,000,000 x 150

 

What is that?