892.970 cm2 to four significant figures

Explanation:

There is a trick to this. Counting out the 4 places is easy enough.

Start at the 8 and count to your right. You land on the nine, but that is not quite your answer.

The 7 influences the 9 and the nine gets bumped up which makes it a 10. but you just record the zero part. The 1 gets added to the 2.

That in turn influences the 2 which makes it a three. So your answer is

893.0

The trick is that you must include the 0. You are guaranteeing that you know the accuracy of the fourth place. Weird but true.

It helps just slight to convert this to scientific notation.

8.9297 * 10^2  = 8.930 * 10^2

You get the same rounding problem as discussed above, but it might be a little easier to see.

You get the same answer and you have to go through the same steps.