0:00:00.000,0:00:00.550


0:00:00.550,0:00:05.400
Let's add 19 and[br]3/18 to 18 and 2/3.

0:00:05.400,0:00:07.640
So I like to separate out[br]the whole number parts

0:00:07.640,0:00:08.740
from the fraction parts.

0:00:08.740,0:00:14.590
So 19 and 3/18 is the same[br]thing as 19 plus 3/18.

0:00:14.590,0:00:18.700
And to that, we are[br]going to add 18 and 2/3,

0:00:18.700,0:00:23.690
which is the same[br]thing as 18 plus 2/3.

0:00:23.690,0:00:26.520
Now we can separately add[br]the whole number parts.

0:00:26.520,0:00:29.295
So we could add[br]the 19 to the 18.

0:00:29.295,0:00:33.210
So we could do 19 plus 18.

0:00:33.210,0:00:36.960
And then we can add[br]the fraction parts--

0:00:36.960,0:00:42.896
let me do this in green--[br]plus 3/18 plus 2/3.

0:00:42.896,0:00:46.080


0:00:46.080,0:00:48.970
Now 19/18, pretty[br]straightforward.

0:00:48.970,0:00:49.830
That is what?

0:00:49.830,0:00:50.330
Let's see.

0:00:50.330,0:00:51.739
19 plus 19 would be 38.

0:00:51.739,0:00:53.405
So this is going to[br]be 1 less than that.

0:00:53.405,0:00:54.880
It's going to be 37.

0:00:54.880,0:00:57.060
So that gives me 37.

0:00:57.060,0:00:59.830
And then 3/18 plus[br]2/3, to add them,

0:00:59.830,0:01:01.640
I need to have the[br]same denominator.

0:01:01.640,0:01:05.530
And the least common[br]multiple of 18 and 3 is 18.

0:01:05.530,0:01:09.250
So let's convert 2/3[br]to something over 18.

0:01:09.250,0:01:13.810
So 2/3, if I want to write[br]it as something over 18,

0:01:13.810,0:01:16.550
well, I multiplied[br]the denominator by 6,

0:01:16.550,0:01:19.060
so I'd also have to[br]multiply the numerator by 6.

0:01:19.060,0:01:22.580
So it's the same thing as 12/18.

0:01:22.580,0:01:27.390
So I can rewrite 2/3 as 12/18.

0:01:27.390,0:01:29.390
And now I can add these[br]two things together.

0:01:29.390,0:01:33.240
That's going to be-- so[br]I have 37 plus-- it's

0:01:33.240,0:01:37.960
going to be something over[br]18-- plus something over 18.

0:01:37.960,0:01:42.452
3 plus 12 is 15, plus 15/18.

0:01:42.452,0:01:44.160
And so expressing this[br]as a mixed number,

0:01:44.160,0:01:48.930
I get 37 and 15/18.

0:01:48.930,0:01:51.050
And that's the right number.

0:01:51.050,0:01:52.520
But we can simplify[br]it even more.

0:01:52.520,0:01:54.160
We can simplify the 15/18.

0:01:54.160,0:01:58.330
Both the numerator and the[br]denominator are divisible by 3.

0:01:58.330,0:02:00.084
So let's divide them both by 3.

0:02:00.084,0:02:02.000
And we're not changing[br]the value because we're

0:02:02.000,0:02:04.680
doing the same thing to the[br]numerator and the denominator.

0:02:04.680,0:02:09.788
And so this gives us,[br]we still have our 37,

0:02:09.788,0:02:14.400
but the numerator is now 5,[br]and the denominator is now 6.

0:02:14.400,0:02:16.020
So we get 37 and 5/6.

0:02:16.020,0:02:19.080


0:02:19.080,0:02:20.850
And we're done.