I made a set of images that people might like to use as models for thinking about the doubles facts. The ideas come from the work of John Van de Walle – I just added the clip art! Enjoy!
Carole
PS – The double nines are drawn from the image of an 18-wheeler… 2 wheels on the axel of the truck (under the cab), then 4 on the next axel and 4 on the next, then 4 and 4 more on the last 2 axels… Tricky, but apparently THAT’S what makes an 18-wheeler an 18-wheeler!
Mathematical Thinking 