How a simple warm up can lead to learning

New Zealand Graduating Teacher Standard 1.a

Graduating Teachers have content knowledge appropriate to the learners and learning areas of their programme.

It was just a simple maths warm up called ‘guess my number.’ It’s kind of like hangman but for maths.

Now I’m sure you are rolling your eyeballs.

Hangman?

Seriously?

But the thing is this game is great for getting kids to use place value so long as you can make the thinking visible.

So we start with the learning.

WALHT: use place value to guess a 3 digit number.

I use 3 digits because that’s about where my year 1/2 learners are at. But you can go down to two digit numbers to start with or up to 5 or 6 digits depending on what your students learning needs are.

The success criteria is simple  students will be able to explain how they guessed the number using place value. This means even mistakes are opportunities for learning if you ask the right questions.

I write 3 spaces and the students start guessing the number and put ticks and crosses beside the guess according to whether each number has a correct answer. So if a student guesses 124, I will tick 1 and 4 if the ‘answer’ is 194. Nine gets an X.

I will always give a ‘tick’ for one number on the first guess to start the students off.

From the second guess I will start asking questions.

How did you know to pick that number? What digits have ticks?  What do you think would be a better guess for next time (if a student makes a guess that hasn’t used place value)? What digits do you think will have ticks?

A student wins when they are able to explain how the guessed all three places (which I point out is the success criteria for the game before we start playing).

What was amazing wasn’t how quickly students started using place value to make their guesses, but how they chose to adapt the game.

At the end of one warm up a student commented that he wanted me to record a plus or minus sign instead of ticks and crosses. So for the next lesson I use his suggestion and away we went. The students quickly figured out that using plus and minus signs meant the game was a lot easier because the symbols told them whether to pick a number greater than or less than the previous guess. So not only were the students were not only using the language of maths they had stumbled upon a key concept of probability, chance = favourable outcomes/total possible outcomes, and were now using it to improve their odds! I hadn’t even considered using plus or minus as a way to record answer which showes how agile children’s minds are when the right questions are asked.

I was dumbstruck that a simple warm up yielded such great learning moments.

The students have now decided guess my number is too easy and want to guess 4 digit numbers.

Who am I to argue?