Adding to 10

- [Voiceover] We've got three bananas here. One, two, three. So I'm starting with three bananas and I want to add some number of bananas so that I end up with 10 bananas. So this is what I'm starting with. I'm starting with three and I want to end up with 10. One, two, three, four, five, six, seven, eight, nine, ten. So what do I have to add to the three to get to 10? I encourage you to pause this video and try this out on your own. So let's work through this. So let's just start adding bananas. So that's three. So now let me add a fourth. That would be my fourth banana. Five bananas. Six bananas. Seven bananas. Eight bananas. Nine bananas. And ten bananas. So how many bananas did I add? So now I added some number of bananas here. So in total I have one, two, three, four, five, six, seven, eight, nine, ten. So how many did I have to add to the three in order to get to the total of 10 in order to get this 10 right over here? We could just count these. This is one, this is two, this is three, four, five, six, seven. I added seven bananas. I added seven bananas to the original three bananas to get to 10. So three plus seven is equal to 10. And you can see that what we have on this left side is indeed equal to what we have on the right side. On the left side we have one, two, three, four, five, six, seven, eight, nine, ten bananas and on the right hand side we have one, two, three, four, five, six, seven, eight, nine, ten. So they are indeed equal.