 If we pick a couple of larger numbers, like say 23 plus 27, we know we should get 50 out. If we do the arithmetic in binary, it will look a little different. So there's 23 in binary, 27 is, and we'll just add these together one bit at a time. One plus one is zero, carry a one. One plus one plus one is one, carry a one. One plus one is ten. One plus zero plus one is ten. One plus one plus one is eleven. So we get this for hopefully fifty. And if we scroll down, we'll see that yes, this is indeed fifty in decimal. In octal, those same two numbers are twenty-seven for twenty-three, and thirty-three for twenty-seven. So seven plus three, remember in octal, I can't go past eight. So as soon as I add seven plus one, I get to eight or ten, and then I have to carry something. So I actually have twelve here, so I'll write down the two and carry the one. One plus two plus three is still six, because six is less than eight. So I'll write down the six, and if I go forward and check, I do get sixty-two on my number one as well. In hexadecimal, it's the same thing, so I have seventeen for twenty-three and one b for twenty-seven. So now this is going to be a little more complicated, maybe you've forgotten what seven plus b is. If we go back, so b is eleven, okay, so if I'm doing this in decimal, I've got eleven plus seven is eighteen. What is eighteen now in hexadecimal? So I'm working in groups of sixteen, so I've got a sixteen plus two, also gives me eighteen. So I will write this as twelve instead, so I've got sixteen plus two. And then I've got one plus one plus one is three, I get thirty-two, and if I scroll down, yes I see thirty-two is my hexadecimal number.