Ones and tens
Current time:0:00Total duration:2:55
Place value example: 25
Voiceover:What I want to do in this video is think a little bit about what numbers really represent. Let's say someone were to write down the number 25. So what does this really mean? Well the five here, this is in the one's place so it literally represents five ones. And this two right over here, this is in the 10's place, so let me write that down. That's the 10's place, that's the one's place, so this represents two 10s. What do I mean by that? Well another way to write this is this two represents two 10s, just let me write that down. This is equal to two 10s plus five ones. Now what are two 10s? Well that's literally if you can imagine a 10 being a block of 10 things, so you could imagine if this was a 10 right over here. Let me copy and paste this, so copy. So this is going to be the same thing, this is going to be equal to, you have your two 10s, so one 10 and two tens, so you have your two 10s. So that's your two 10s right over there, that really represents 20 plus your five ones. Plus your five ones. Well if this is a one right over here, and I'm just representing it as kind of one vertical bar, five ones are going to look like, your going to have one, two, I think you see where this is going, three, four, and five. And so these are all different ways of representing the same quantity. 25 is two 10s and five ones. This two is in the 10's place, the five is in the one's place. So two 10s plus five ones, so you could then view it as two groups of 10 plus five ones right over here. And what's this going to be the same thing as? Well two groups of 10, this is the same thing as 20 and this over here is equal to five. So once again, all ways to represent 25. You can view this as two 10s plus five ones or you can view this as 20, let me write this down, 25 you could view because this two is two 10s that represents 20 plus the five ones.