0:00:00.808,0:00:05.740 Let's think about what it means to add numbers. 0:00:05.740,0:00:14.674 So let's start with one. [br]One plus -- one plus one. 0:00:14.674,0:00:18.301 What is this going to be equal to? 0:00:19.207,0:00:24.097 One way to think about this is [br]we have one thing. 0:00:24.097,0:00:28.953 And I will -- that thing will be a purple circle. 0:00:28.953,0:00:31.497 So let me put that here. 0:00:31.497,0:00:33.427 So that's this 1 thing. 0:00:33.427,0:00:35.512 I'm just going to represent it with a purple circle. 0:00:35.529,0:00:37.479 And I'm going to add another 1 thing. 0:00:37.479,0:00:40.069 And since this is in blue, [br]I'll make that other circle. 0:00:40.069,0:00:41.835 I'll make that in blue as well. 0:00:42.277,0:00:44.802 So, let me put that right over here. 0:00:45.314,0:00:48.185 So, 1 plus 1. 1 plus 1. 0:00:48.384,0:00:51.642 How many total circles do I now have? 0:00:51.848,0:00:54.529 Well, I now have 2 circles. 0:00:55.030,0:00:57.666 I now have 2 circles. 0:00:57.994,0:01:04.226 1 plus 1 is equal to 2. 0:01:04.649,0:01:07.910 OK, you're saying, "All right, Sal, that makes sense." 0:01:07.920,0:01:11.167 Let's do this with larger numbers. 0:01:11.419,0:01:14.941 So let's say we want to know what equals-- 0:01:14.948,0:01:18.673 and I'll put a question mark over here. [br]So, question mark. 0:01:19.013,0:01:20.783 What equals -- 0:01:20.793,0:01:34.029 So something is equal to, let's say, 2, 2, 2 plus 3. 0:01:34.029,0:01:38.077 Something is equal to 2 plus 3. 0:01:38.077,0:01:41.431 What is this something going to be? 0:01:41.751,0:01:45.530 And I encourage you to pause the video [br]and think about it on your own. 0:01:46.234,0:01:48.879 Well, you can view this as, [br]I have 2 objects, 0:01:48.879,0:01:51.131 and then I am going to add[br]another 3 objects. 0:01:51.131,0:01:54.116 How many total objects would I have? 0:01:54.116,0:02:01.062 So you have your 2 objects, [br]which I'll use purple circles again. 0:02:01.071,0:02:02.430 So let me -- 0:02:02.988,0:02:09.396 Let me, so we have 1 and 2 purple circles. 0:02:09.396,0:02:11.066 This is the 2 right over here. 0:02:11.066,0:02:14.074 And then to that, [br]we're going to add 3 more. 0:02:14.083,0:02:15.665 3 more circles. 0:02:15.665,0:02:19.766 And I'll represent those in blue, [br]because we wrote the 3 there in blue. 0:02:20.155,0:02:28.366 So that is 1, 2, and 3. 0:02:29.542,0:02:33.212 So how many total circles do we now have? 0:02:33.714,0:02:38.599 Well, we can count them. [br]We have 1,2,3,4,5. 0:02:38.599,0:02:45.023 In fact, let me count that. [br]1,2,3,4,5 circles. 0:02:45.282,0:02:46.806 So 2 plus 3 0:02:46.806,0:02:50.799 2 things plus another 3 things [br]are 5 things. 0:02:50.799,0:02:54.799 So our question mark over here [br]is equal to 5. 0:02:55.049,0:02:56.821 So, instead of writing the question mark 0:02:56.821,0:02:59.699 right over here, let me clear that out. 0:02:59.699,0:03:02.236 I could say 5 is equal to -- 0:03:02.733,0:03:09.728 I could write down that 5 [br]is equal to 2 plus 3.