Difference of 4

This is one of my favoruite early lessons, and really lends itself to mixed ability Y7. I'm posting it in response to the mathchat discussion tonight.

Start with a 2x2 grid, and put numbers in the spaces...

Having done this, drawe a few arrows, and do some times tables...

Followed by some adding...











Then, simply - the difference between 46 and 64 is 18.

Questions you can ask...

"Can you choose numbers that give you a difference of 4"

"What happens if you use the same numbers, in a different order"

"What happens if you add 1 to every number"

"Are there any differences you cannot make"

"what happens if you put numbers in in a pattern - 2,4,6,8, etc"

"Is there more than 1 way to make a difference of 4?"

....

It is a lot of fun (and I take no original credit for the lesson. Picked it up on my PGCE many moons ago (OK - 1995/96!)