Hey having some trouble. Multiplying 500,000 * ((√3)/(2)) by hand.
Do it like this. 500,000 = 5 x 10^5, √3 = 1.7 (these you just have to memorize: √2 = 1.4, and √3 = 1.7).
So we have 500,000 * ((√3)/(2)) = (5 x 10^5) * (1.7/2).
Since 5/2 = 2.5, we have:
(2.5 x 10^5)*(1.7) = (25 x 10^-1 x 10^5)*(17 x 10^-1)
= (25 x 17)*(10^3)
At this point, you could either estimate the answer to be ~ 20 x 20 * 10^3 ~ 400,000 (remember if you choose to round 17 up to 20, you should probably round the other number 25 down to balance it, so you don't overestimate the answer).
Or, it's simple enough to actually multiply out 25 x 17 = 425, so the more exact answer is 425,000.