Tables Without Tens
Stage: 2 Challenge Level: 
Try looking along rows, up and down columns and perhaps along
diagonals for patterns in the digits.
When you're finding repeats, you might want to imagine extending
the rows to $11$ lots of the number, $12$ lots, $13$ lots
etc.
When you're trying to explain the patterns, don't forget how you've
made each row in the first place!
Published April 2006,November 2009,December 2009.