The best estimate is the true value.
609.
To estimate the product of 87 times 403, you can round both numbers to the nearest tens or hundreds. Rounding 87 to 90 and 403 to 400, you get 90 x 400 = 36,000. This is a rough estimate of the product of 87 times 403.
7x87 is about 7x90, which equals 630
in my best estimate, about 95%.
6 divided 87 = 0.06896551724137931
43.5
0.0124
0.8851
1.93
0.0833
578
1.45