- Concept Videos
- Solutions 44

Round each number to three significan t figures.

a. 79,845.82

b. 1.548937 X 10^{7}

c. 2.3499999995

d. 0.000045389

Hey guys, in this question we're asked to figure out 3 sig figs for each one of these numbers given so for the first one we want to 3 sig figs at the end so we want these 3 numbers, this is a 4 here which would mean that 8 doesn't get rounded up to 9, now it would be incorrect if you added if you came up with this answer that's because....Ops and it should be 98 this is incorrect because when it has no decimal point we're going to go from right to left if your first number is a 0 that means you have an infinite number of significant figures but we need 3 significant figures so that means instead of writing it in this form we need to change it into scientific notation so this becomes 7.98x10^4, now this number has 3 sig figs.

For the next one, we want 3 digits there is an 8 here which means that 4 gets rounded up to 5 so this becomes 1.55x10^7.

For the next one, we want 3 digits again this happens to be a 9 next to it so that becomes 2.35.

For this last one we want 3 digits so remember here when we have a decimal point we go left to right, we count the first non-zero number so this is our first non-zero number so 1 2 3 these 3 numbers are the ones that we want and then there's an 8 here which means that 3 gets rounded up to 4 so we can write it in two different ways, we can you are either write it as 0.0000454 or you can write it in scientific notation 4.54x10^-5 , both would be acceptable answers and then these are the answers that we get when we round each of them to 3 significant figures.