[Script Info]
Title: 
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:00.44,0:00:05.01,Default,,0000,0000,0000,,We're told that Linde isn't sure\Nhow to subtract 853...
Dialogue: 0,0:00:07.22,0:00:09.83,Default,,0000,0000,0000,,We are told Linde isn't sure
Dialogue: 0,0:00:09.83,0:00:14.00,Default,,0000,0000,0000,,how to subtract 853 minus 283.
Dialogue: 0,0:00:14.26,0:00:16.64,Default,,0000,0000,0000,,Help Linde by choosing an expression
Dialogue: 0,0:00:16.64,0:00:21.44,Default,,0000,0000,0000,,that is the same as 853 minus 283.
Dialogue: 0,0:00:21.53,0:00:24.46,Default,,0000,0000,0000,,So, pause this video and see\Nif you can answer it on your own
Dialogue: 0,0:00:24.51,0:00:26.72,Default,,0000,0000,0000,,before we work through it together.
Dialogue: 0,0:00:26.80,0:00:29.30,Default,,0000,0000,0000,,Alright, now that we look\Nat all the choices,
Dialogue: 0,0:00:29.30,0:00:31.32,Default,,0000,0000,0000,,they all start with 853.
Dialogue: 0,0:00:31.36,0:00:34.72,Default,,0000,0000,0000,,Now, this first choice\Nthey subtract out 200
Dialogue: 0,0:00:34.78,0:00:37.01,Default,,0000,0000,0000,,That makes sense\Nbecause we have 2 hundreds
Dialogue: 0,0:00:37.01,0:00:38.52,Default,,0000,0000,0000,,right over there.
Dialogue: 0,0:00:38.65,0:00:40.73,Default,,0000,0000,0000,,Then they subtract out 50
Dialogue: 0,0:00:40.75,0:00:43.04,Default,,0000,0000,0000,,and then they subtract out 3,
Dialogue: 0,0:00:43.45,0:00:46.05,Default,,0000,0000,0000,,So, the 200 and the 3 make sense.
Dialogue: 0,0:00:46.15,0:00:49.21,Default,,0000,0000,0000,,You can view 853 minus 283
Dialogue: 0,0:00:49.29,0:00:54.05,Default,,0000,0000,0000,,as 853 minus 200,
Dialogue: 0,0:00:55.20,0:00:57.91,Default,,0000,0000,0000,,minus 80, 8 tens right here,
Dialogue: 0,0:00:57.93,0:00:59.18,Default,,0000,0000,0000,,minus 3.
Dialogue: 0,0:00:59.18,0:01:01.22,Default,,0000,0000,0000,,But that's not what they wrote over here.
Dialogue: 0,0:01:01.24,0:01:03.28,Default,,0000,0000,0000,,Instead of putting 80 here,\Nthey put a 50.
Dialogue: 0,0:01:03.33,0:01:04.63,Default,,0000,0000,0000,,So we can rule that out.
Dialogue: 0,0:01:04.66,0:01:06.61,Default,,0000,0000,0000,,Here we have 853 minus 20
Dialogue: 0,0:01:06.65,0:01:08.72,Default,,0000,0000,0000,,minus 800 minus 3.
Dialogue: 0,0:01:08.77,0:01:11.03,Default,,0000,0000,0000,,Well, this is a little bit strange
Dialogue: 0,0:01:11.06,0:01:13.66,Default,,0000,0000,0000,,because we don't have 2 tens,\Nwe have 2 hundreds
Dialogue: 0,0:01:13.66,0:01:16.70,Default,,0000,0000,0000,,and we don't have 8 hundreds,\Nwe have 8 tens,
Dialogue: 0,0:01:16.74,0:01:18.71,Default,,0000,0000,0000,,so this is also incorrect.
Dialogue: 0,0:01:18.87,0:01:20.89,Default,,0000,0000,0000,,Now, it's probably going to be this one,
Dialogue: 0,0:01:20.91,0:01:23.63,Default,,0000,0000,0000,,but let's just make sure\Nwe feel comfortable with this.
Dialogue: 0,0:01:23.67,0:01:26.60,Default,,0000,0000,0000,,So, this one has 853 minus 200,
Dialogue: 0,0:01:26.67,0:01:28.62,Default,,0000,0000,0000,,minus 53.
Dialogue: 0,0:01:28.68,0:01:30.60,Default,,0000,0000,0000,,minus 30.
Dialogue: 0,0:01:30.92,0:01:33.38,Default,,0000,0000,0000,,Does that make sense?
Dialogue: 0,0:01:33.41,0:01:34.95,Default,,0000,0000,0000,,Well, let's think about it.
Dialogue: 0,0:01:35.04,0:01:36.30,Default,,0000,0000,0000,,What they're doing,
Dialogue: 0,0:01:36.30,0:01:38.64,Default,,0000,0000,0000,,is they're subtracting out first the 200,
Dialogue: 0,0:01:38.64,0:01:41.29,Default,,0000,0000,0000,,so that this part right over here,\Nso that makes sense.
Dialogue: 0,0:01:41.31,0:01:43.14,Default,,0000,0000,0000,,They're subtracting out first that.
Dialogue: 0,0:01:43.27,0:01:45.16,Default,,0000,0000,0000,,And then they're subtracting out 53
Dialogue: 0,0:01:45.20,0:01:47.03,Default,,0000,0000,0000,,and then subtracting out 30.
Dialogue: 0,0:01:47.03,0:01:48.78,Default,,0000,0000,0000,,Well, that is the same thing
Dialogue: 0,0:01:48.78,0:01:50.63,Default,,0000,0000,0000,,as subtracting out 83,
Dialogue: 0,0:01:50.63,0:01:52.34,Default,,0000,0000,0000,,because subtracting out 83
Dialogue: 0,0:01:52.34,0:01:54.41,Default,,0000,0000,0000,,is the same thing\Nas subtracting out 53 and
Dialogue: 0,0:01:54.41,0:01:56.18,Default,,0000,0000,0000,,and then subtracting 30.
Dialogue: 0,0:01:56.21,0:01:57.44,Default,,0000,0000,0000,,53 plus 30 is 83.
Dialogue: 0,0:01:57.45,0:01:58.85,Default,,0000,0000,0000,,Now, you might be wondering
Dialogue: 0,0:01:58.85,0:02:00.56,Default,,0000,0000,0000,,why would they even do it this way?
Dialogue: 0,0:02:00.59,0:02:02.72,Default,,0000,0000,0000,,What is easier to do in your head?
Dialogue: 0,0:02:02.78,0:02:06.73,Default,,0000,0000,0000,,853 minus 200 is 653.
Dialogue: 0,0:02:07.12,0:02:09.63,Default,,0000,0000,0000,,You take away 53 from that,
Dialogue: 0,0:02:10.17,0:02:12.30,Default,,0000,0000,0000,,so you take away 53 from that,
Dialogue: 0,0:02:12.30,0:02:14.56,Default,,0000,0000,0000,,and you're going to be left with 600.
Dialogue: 0,0:02:15.01,0:02:17.15,Default,,0000,0000,0000,,And then 600 minus 30
Dialogue: 0,0:02:17.15,0:02:19.15,Default,,0000,0000,0000,,— you might recognize that,
Dialogue: 0,0:02:19.15,0:02:21.83,Default,,0000,0000,0000,,you could do 60 tens minus 3 tens —
Dialogue: 0,0:02:22.18,0:02:23.54,Default,,0000,0000,0000,,it's going to be 57 tens,
Dialogue: 0,0:02:23.59,0:02:25.61,Default,,0000,0000,0000,,or you might be able\Nto do it in your head
Dialogue: 0,0:02:25.62,0:02:28.47,Default,,0000,0000,0000,,600 minus 30 is 570.
Dialogue: 0,0:02:28.54,0:02:30.37,Default,,0000,0000,0000,,So, that's why they broke out,
Dialogue: 0,0:02:30.37,0:02:31.89,Default,,0000,0000,0000,,they broke up the 83.
Dialogue: 0,0:02:31.94,0:02:34.10,Default,,0000,0000,0000,,Instead of just breaking it up\Ninto 80 and 3,
Dialogue: 0,0:02:34.12,0:02:38.49,Default,,0000,0000,0000,,they broke it up into 53 and 30\Nto match this 53 over here.
Dialogue: 0,0:02:38.69,0:02:41.15,Default,,0000,0000,0000,,It's easier to work out the result.
Dialogue: 0,0:02:41.43,0:02:42.69,Default,,0000,0000,0000,,Let's do another example.
Dialogue: 0,0:02:42.71,0:02:45.26,Default,,0000,0000,0000,,So, here we're asked to fill in the blank.
Dialogue: 0,0:02:45.27,0:02:50.28,Default,,0000,0000,0000,,They say, 143 minus 79\Nis the same as "blank" minus 80.
Dialogue: 0,0:02:50.37,0:02:53.23,Default,,0000,0000,0000,,So, pause this video\Nand see if you can figure this out.
Dialogue: 0,0:02:53.48,0:02:55.70,Default,,0000,0000,0000,,So, the key here is to realize
Dialogue: 0,0:02:55.72,0:02:57.53,Default,,0000,0000,0000,,is, when you have a difference here,
Dialogue: 0,0:02:57.53,0:02:59.85,Default,,0000,0000,0000,,as long as you add or subtract\Nthe same amount
Dialogue: 0,0:02:59.89,0:03:01.17,Default,,0000,0000,0000,,to both of these,
Dialogue: 0,0:03:01.19,0:03:03.18,Default,,0000,0000,0000,,the difference will be the same.
Dialogue: 0,0:03:03.19,0:03:06.29,Default,,0000,0000,0000,,So, it looks like they tried\Nto turn 79 into,
Dialogue: 0,0:03:06.38,0:03:10.24,Default,,0000,0000,0000,,it looks like they turned\Nthe 79 into an 80,
Dialogue: 0,0:03:10.34,0:03:12.17,Default,,0000,0000,0000,,by adding 1
Dialogue: 0,0:03:12.20,0:03:14.50,Default,,0000,0000,0000,,and so if we want the difference\Nto be the same,
Dialogue: 0,0:03:14.52,0:03:17.98,Default,,0000,0000,0000,,we would add 1 to the 143 as well,
Dialogue: 0,0:03:18.30,0:03:21.56,Default,,0000,0000,0000,,So, 143 plus 1 is 144.
Dialogue: 0,0:03:21.59,0:03:23.70,Default,,0000,0000,0000,,If we add one to both of these numbers,
Dialogue: 0,0:03:23.74,0:03:25.88,Default,,0000,0000,0000,,the difference would be the same.
Dialogue: 0,0:03:25.92,0:03:27.32,Default,,0000,0000,0000,,And we're done.
Dialogue: 0,0:03:27.45,0:03:29.49,Default,,0000,0000,0000,,So it's 144 minus 80.