Pam  00:00

Hey, fellow mathers! Welcome to the podcast where Math is Figure-Out-Able. I'm Pam. 

Kim  00:06

And I'm Kim. 

Pam  00:06

And this episode is a MathStratChat episode where we chat about our math strategies. Every Wednesday evening, I throw out a math problem on social media, and people from around the world chat about the strategies they use,  and comment on each other's thinking. 

Kim  00:19

Alright, this Wednesday, the problem was 3,002 minus 1,905. How would you solve this problem? Go ahead and solve it any way you want, and then listen in.

Pam  00:32

So, 3,002 minus 1-9-0-5. 1,905. Alright, go. Can I go first? 

Kim  00:39

Sure. 

Pam  00:40

So, I'm going to Constant Difference again.

Kim  00:43

Okay.

Pam  00:43

Meaning, I'm going to plunk both those numbers down on a number line and think about how far apart they are but not where they are. 

Kim  00:50

Okay.

Pam  00:51

I would like to subtract a number that's delightful. And to me, 1,905 is okay, but it's not as delightful as I wish, so I'm going to take that distance down to... I'm going to shift them both down 5. So, the 1,905 becomes 1,900. And the 3,002 down 5 becomes 2,000...I have to think here...97. Ha, I'm alive. I'm awake. Is that right? Yes. That's 5 down. Okay, so now I end up with an equivalent problem. That's funny. Equipment problem a 2,097 subtract 1, 900. No, I don't like that. Look at that. Look at me. Waking up and not liking what I just did. 

Kim  01:31

You want to change? You can change your mind.

Pam  01:33

Do I get to change my mind? 

Kim  01:34

Absolutely.

Pam  01:35

Well, now what am I... I got to think about what I'm... Alright, alright, I'm changing my mind. From 1,905. This is thinking live, ya'll, on the podcast right now. I'm going to take 1,905 up to 2000. 

Kim  01:48

Okay.

Pam  01:48

So, that's 95. That means I have to add 3,002 also plus 95. So, that's 3,097. So, now I have an equivalent problem of 3,097 subtract 2,000. Yeah, like that better. So, 3097 subtract 2,000 is 1,097. 

Kim  02:09

Yeah, I like it. I also like that sometimes you think something is friendly when you shift, and it doesn't end up friendlier, so you just shift again. 

Pam  02:20

Just try it again. 

Kim  02:21

Yeah, totally fine.

Pam  02:22

Yeah. Yeah, you kind of freed me up that one day when I thought mathematicians could instantly know the best thing to do right off the bat. And we probably do that almost too quickly here sometimes...

Kim  02:32

Yeah.

Pam  02:32

...in MathStratChat. But that was real. That was me thinking, "Hey, yeah, I'm just going to turn 1905 into 1900 Sure, that will..." No, that's not good at all."

Kim  02:40

Yeah, yeah. 

Pam  02:41

Or at least, (unclear).

Kim  02:41

Well, because the whole point of Constant Difference is to find an equivalent problem that's nicer. 

Pam  02:46

I mean, now that I think about it, 2097 minus 1900. I could still think about the distance between those numbers. Let's just a 1,097 Duh. Like, it's not bad. 

Kim  02:58

It is also very real, people, that we have a microphone in our face. So, (unclear)

Pam  03:07

So, my brain caught on that one. When I thought about 2,097 minus 1900, I was thinking removal, not distance. But if that distance is just 100 up to the 2,000, right? And then... Or, I mean a 1,000 up, and then 97. Bam! Alright.

Kim  03:22

Nice. Nice. 

Pam  03:23

So close and yet so far. What are you going to do?

Kim  03:26

I also want to shift the distance because that's a little funky, but I actually shifted down a little bit. Because the 3,002 just feels so close to 3,000. 

Pam  03:37

Okay. (unclear).

Kim  03:38

So, I shifted to the left to make the new problem 3,000 minus 1,903. On a number line. I said to the left because I shifted on number line. So, my new problem is 3,000 minus 1,903. 

Pam  03:55

Okay. 

Kim  03:58

And I also found the distance. And, you know, that just feels I Have, You Needy for me, so...

Pam  04:05

Did you just say I Have, You Needy?

Kim  04:08

Is that my new phrase?

Pam  04:09

I think so. That's hilarious. I Have, You Needy. I like. Like, did you just literally go from 1,903 up to 2,000? And that's 97?

Kim  04:19

Yeah, I think because I went 197 in my head. Like, I started looking at the 1903. 

Pam  04:27

Yeah.

Kim  04:28

And I went 197. I mean, 1,097 Yeah. 

Pam  04:32

Oh, you can see that 1,000.

Kim  04:34

Yeah.

Pam  04:35

I had to see the 97 first, and then the 1000.

Kim  04:37

Oh, yeah, either way.  Okay. Cool. 1,097. 

Pam  04:41

Yeah, so you often will change the first number in a subtraction problem to be a nice number, and then subtract. And that is not my fave. I would prefer to change the second number in the subtraction to be a nice number. 

Kim  04:54

Yeah. 

Pam  04:55

Yeah.

Kim  04:56

I think a lot of people will. But you could play I Have, You Need some more. Alright.

Pam  05:02

Sounds good.

Kim  05:03

We can't wait to see.

Pam  05:05

So, then I can be I Have, You Needy too?

Kim  05:09

We need a shirt. I Have, You Needy. Alright people. What are you going to do this week? Join us on MathStratChat. Let us know how you think about the problem, and comment on each other's thinking.

Pam  05:20

Ya'll, we post the problems on Wednesdays around 7pm Central time. When you answer, tag me and use the hashtag MathStratChat. Then join us here to hear how we're thinking about the problem. Ya'll, thanks for being part of the Math is Figure-Out-Able movement because Math is Figure-Out-Able!