we have 4 significant figures in this problem because
4.762 (four numbers) is not 4.7620 (five )
so the problem is really
2.802 - 4.762 = -1.960
when using significant figures, why is 2.8023 - 4.762 = -1.960 instead of -1.961
3 answers
so does this apply to everything else where you round all the numbers down to the number with the least significant figures?
yes, if you only know one of them to 3 decimal places, there is no point in carrying more in the others.