00:03
We're going to be adding and subtracting some problems, very basic problems, but we need to use significant figures to express our answer.
00:14
So remember that whenever you are adding or you are subtracting, you need to express your answer with the least amount of decimal places.
00:35
So how do we do that? very simple.
00:39
So what you're going to do is that you're going to count how many decimal places this number have.
00:46
So this number has two decimal places.
00:50
This number has three decimal places.
00:54
So i know that my answer needs to have one and two decimal places.
01:03
Whatever is at the front doesn't matter.
01:06
But after your decimal point you need to have two places.
01:11
So let's put up our calculator and we're going to put that number in there.
01:19
So i have 45 .48 that i'm going to be adding to 8 .057 and that is giving us that number.
01:33
So i know that after this decimal i need to have only two places.
01:38
So we said the 53.
01:40
But since this is 7 or more, i need to add one more to the 3.
01:44
So your answer is going to be 53 .54.
01:53
And do not forget your units.
01:56
These are centimeters.
02:00
Let's do the same with this one.
02:01
This one has two decimal places.
02:05
This one have one decimal place.
02:09
This one right here has one, two, and three.
02:13
So i need to choose one.
02:15
So my answer is going to have one decimal place.
02:20
And we're going to do the same.
02:22
Let's get out of calculators.
02:25
And we're going to put that number, 23 .45 plus 104 .1 plus 0 .25.
02:35
All of those are grams.
02:38
So i know in here that whatever is before the decimal point don't count.
02:45
You need to write them, of course, but it doesn't count.
02:48
And i have a five in here.
02:50
But since i have a seven at the right, i need to add one.
02:54
So this is going to be 1 .27...