## Tuesday, October 7, 2014

### Mystery Numbers

In my math group this morning, we tried our hands at solving a problem to find the mystery number:

If you have trouble reading this (sorry for the glare), it says: "This mystery number has 4 digits. Each digit is an odd number. None of the digits is 9. Every digit is different. The smallest digit is in the thousands place. The largest digit is in the ones place. Now you should have two possible numbers. The mystery number is the greater of the two."

I gave students about 5 minutes to come up with an answer. One child got it correct, and many of the others were close. It was clear that we need more practice with this sort of logic problem - not so much to come up with the correct answer (although that is, of course, important too) - but to learn to struggle with not knowing something right away.

In this particular scenario, we talked about 1) what a digit is, 2) what a number is, 3) difference between odd and even, 4) place value of thousands, hundreds, tens, ones, and 5) what "greater" means. You can make your own puzzles at home! It would be great reinforcement of some of the concepts we are working on in math.

#### 1 comment:

Christopher Matthews said...

We've been playing this at home. Cool game! I find the biggest challenge is coming up with the puzzle, and we take turns doing it, and Eliza's great at it. Which is awesome.