<span>So we need to explain how we know 21/30 is greater than 2/3. Well lets expand 2/3 by multiplying the numerator and the denumerator by 10. That way we get 20 / 30. Since 21/30 has 1/30 more than 20/30 we can clearly see that 21/30 is greater than 20/30 or 2/3.</span>
As a percent is out of 100% or 1 (as a whole number), the best thing to do is multiply it by ten, until you get a whole number. As you cannot have a decimal in a percentage. 2.45x10= 24.5. This is still a decimal, so you need to multiply it be ten again, 24.5x10= 245.
Therefore, 2.45 is a percent is 245%
Each side after the cut-out is (s-2c) where s is the original side length and c is the size of the cut so:
V=hlw, h=x and l and w are both (x-8)
V=x(x-8)(x-8)
V=x(x^2-16x+64)
V=x^3-16x^2+64x