Michael Strong works through math patterns with six-year-old Alana, starting with subtraction. He guides her to spot that halving the numbers gives the answer: 10-5=5, 100-50=50. She practices counting strategies and begins linking addition and subtraction pairs to solve problems faster.
I hear you won a tournament yesterday.
I did.
Congratulations! How was that?
It was really fun.
Was it hard?
Yes, it was. It's always hard.
And is it hard physically, or is it hard kind of mentally, or in what way is it hard?
Like, um, Um, like if you're doing something like that other people are doing and good at, yeah, that's pretty hard.
I see. Was it close? Did you almost lose some matches?
Yeah, almost, almost lost some matches.
And then you just do your very best and you win? Yeah. Good for you, good for you. Um, I thought we'd check in on math. We haven't talked about math for a while. Can you tell me what you're learning, what you're learning in math?
In math, I would say in my school we're doing math like ST Math. Um, that's one kind of math we do on the iPad, which all of us are almost done with it. Um, do it every year.
Are you adding numbers?
Well, there's all kinds of math in that game, like, um, subtracting, adding, Measurement.
Do you do multiplication and division or not yet?
I don't think so, not yet for me.
Okay. Do you like addition better or subtraction?
Subtraction may be better.
Okay. Let's just see where you are. Do you know what 10 minus 5 is?
5.
There you go, that was easy. How about 20 minus 10?
That's 10.
How about 100 minus 50?
That's probably, um, 50.
Wow, you are good. That's impressive. Um, how about 200 minus 100?
Maybe I'm not so good at that one, but yeah, I'm still learning.
Can you either guess or figure it out?
Maybe. So I would say it's probably 100 or something.
That's exactly right. Tell me how you figured that out.
Because since you said, um, 200 minus 100, I thought it would land on 100.
Um, and I I think the way I sometimes— I look for patterns with numbers. You know what a pattern is?
Yes, I do.
What's an example of a pattern?
Like, say, if this was numbers, 1, 2, 1, 2, or 1, 2, 3, 1, 2, 3.
That's a great example. Actually, the pillow behind your head has patterns of different kind. You see the flower patterns on there?
Yep.
So a pattern is when there are kind of things that repeat. So on the pillow, the flowers repeat over and over again. And you're right, you— those were great examples of number patterns. 1, 2, 1, 2, or 1, 2, 3, 1, 2, 3. So I was thinking that you know what 2 minus 1 is, right?
Yes, I do.
It's— what is it?
1.
And you know what 20 minus 10 is, right?
Yes.
What is it?
10.
And I thought maybe we could— maybe you figured out because there's a pattern, because if 2 minus 1 is 1 and 20 minus 10 is 10, then based on a pattern, what do you think 200 minus 100 would be?
Well, based on the pattern, like 200 or like 100, 200, 100, So that would probably be 100.
Yeah, do you see how, um, going back, let's do the addition version. So 1 plus 1 is 2, 10 plus 10 is 20. What is 100 plus 100?
200.
Now did you know that one or did you figure it out because it's part of the pattern?
Um, I figured it out and I knew it was part of the pattern.
Okay, so now let's see, let's see if we can do a bigger one. What is 1,000 plus 1,000?
2,000.
There you go. And in which case, what is 2,000 minus 1,000?
Probably 1,000.
There you go. Have you ever done numbers this big before?
No, I haven't.
But you see the pattern? You see how they all follow a pattern?
Yeah.
How about what is 1 million plus 1 million?
2 million.
There you go. How about 2 million minus 1 million?
Probably 1 million.
There you go. It seems like a pattern, doesn't it?
Yes, it does.
Um, maybe let's do slightly tricky one— trickier ones. How about what is 20 million minus 10 million?
10 million, probably.
There you go. I think you have this pattern kind of figured out. How about what is 40 million minus 20 million?
20 million.
I think you really have it figured out. Um, I want to be a little bit trickier. What is 15 million minus 5 million?
10 million.
There you go. I guess I'm not tricky enough, am I? Uh, you have these figured out. Let's see, how about— okay, let's go back to small numbers but do a little bit more complicated. Do you know what 24 minus 4 is?
20.
Yeah. How about 24 minus 8.
Maybe not that one.
Aha! Maybe I can find tricky ones for you. So let's see if we can figure out— let's— what do you— how would we figure out 24 minus 8?
So like 24, um, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8. 16.
One way to figure out is to count. That, that's one way we can figure it out. Um, how about, do you know what 20 minus 4 is?
20 minus 4 is probably— yeah, maybe. I don't know, like, those ones, but yeah, I can still figure them out.
You can figure them out by counting, but let's see if we can find an another way to figure them out. How about 20 minus 5? Do you know what 20 minus 5 is?
No.
Okay.
I'll have homework though.
Okay. Um, addition. How about 15 plus 5?
Wait, excuse me, I couldn't—
What is 15 plus 5?
Um, 20.
There you go. And if 15 plus 5 equals 20, what do you think 20 minus 5 is going to be?
15.
There you go. Um, how about what is 20 plus 5?
20 plus 5 is 25.
There you go. What is 25 minus 5?
20 minus 25 minus 5 is 20.
There you go. How about 30 minus 5?
Minus 5 is 25.
There you go. Um, okay, how about 50 minus 5?
That's 45.
Excellent. So it looks like you're getting that pattern. So we know, do you remember what 20 minus 4 is?
Maybe.
What's 20 minus 4?
I'm thinking it could probably be like, like 16.
That's exactly right. How did you figure that out?
Because I knew that if 5, it would be less 1 more than 6.
Oh, I think that's excellent. That's excellent reasoning. You are using your mind to figure things out. So if 20 minus 4 is 16, what do you think 30 minus 4 is?
30 minus 4 is 26.
I think you're finding a pattern. How did you figure that out so fast?
Because, you know, the same thing. It would mean more to 6 than 5.
Yeah, do you see what I mean by calling these things patterns?
Yes, I now do.
Okay, does it seem funny that we call like the flowers and the pillow a pattern and we also call these mathematical things patterns, or does it make sense?
It makes sense.
Okay, well, um, what are you going to do for the rest of the day?
I know we're gonna go to the zoo again. I don't know the rest.
Okay, well, I am delighted that you are looking at mathematical patterns, and so I want you to look at patterns all over everywhere in the world and see where you can see patterns anywhere, okay? Okay. Okay, have a wonderful week, Ilana, and congrats again on your victory yesterday.
Thank you. Bye-bye. Bye, I'll see you next week.
You too.
