This is how they are teaching in the schools I have been in. Great math hack for your kids! I wish I knew this in elementary school. I don't teach multiplication any more this is a great idea for those few facts kids just have a tough time memorizing.
The 100 square challenge! Can you use your knowledge of numbers, patterns and place value to reassemble the 100 square? How about trying it against the timer? Can you even complete more than one square before the time runs out?