Arectangle has a length of 9.00 inches and a width of 4.25 inches. what is the area in square inches. round to the correct significant digits

Let the length of a rectangle be l and the width of that rectangle be w, then the area of the rectangle is given by:

                           

In our problem, l= 9 inches, and w=4.25 inches.

then, 

(square inches)

--------------------------------------------------------------------------------------------------
Remark: we performed the following operation to make the multiplication easier:



we wrote 4.25 as 4+0.25, and multiplied 9 to each of these separately, instead of multiplying 9 to 4.25 directly, using the distributive property

thus making the operation a little easier.
---------------------------------------------------------------------------------------------------- 

38.25 square inches

Remark : 

Asking "Round to the correct significant digits" is not correct. 

The number of significant digits must be stated. 

if we want the number rounded to 3 significant digits 38.25 is 38.6 

if we want the number rounded to 2 significant digits 38.25 is 38.0 

if we want the number rounded to 1 significant digits 38.25 is 40,0

 

The answer is -pie over 2