She will use Surface area formula [2(lb+bh+hl) , where, l= length , b = width and h = height ] to find the area of the four walls excluding the area of windows and doors .
Then she will multiply the amount of paint needed to paint 1 m²(sq.metre) area of wall with the area of the walls of her room .
F - because you must move the decimal place 9 spaces to the left in order to have only a single digit in front of the decimal place. (There can never be more than one otherwise it is no longer scientific notation.
