 Now, once we know a little bit about addition, once we know how to add certain numbers, we can actually use our strategies much more flexibly and much more effectively. So let's take a look at counting on, and we'll assume that we know some additions, and we can use counting on to find the sum, 37 plus 55, and so here's something new. We'll actually try to show this sum found three different ways. So remember, counting on is based on the idea that adding one gives you the number after. So we do want to use counting on in some form. So what that says is we want to find the 55th number after 37. And so we could start by counting by ones from 37. So 37 and the next number after, and I'll represent that by this plus one above the 37, the next number after that is 38, the next number after that is 39, the next number after that is 40. And if I just count by ones, it'll take me quite a while to get to the 55th number. But what's worth noting here is that because I'm at a 10, 40, I can count by tens from this point, and it's really easy to do so. Ten more is 50, again is 60, again is 70, again is 80, again is 90, pause a second here. The only thing to notice here is so far I've added 10, 20, 30, 40, 50, and 3. So so far I've added 53, I do want to add 55, so I have to finish my count one more to 91, one more to 92, and that will get me to my 55th number after 37, and so 37 plus 55 is 92. Well we do want to find the sum three different ways, so we'll try counting on in a slightly different implementation. This time I'll count by tens from 37, so 37, 10 more is 47, to 57, 67, 77, 87. And then I've counted 50, I want to get the 55th number, so I'm going to count one more, two, three, four, and five, and that takes me up to 92 again. So the 55th number after 37 is 92. Well a third way uses some of our addition facts, so I can complete 37 to 40 by adding three, that takes me to 40, I want to add 55, so I'll add 50, that so far gets me an add of 53, so I'm going to add two more to get the 55th number after 37, and so I get my sum 37 plus 55 takes me to 92. So there's three different ways of using counting on to find the sum 37 plus 55.