OK, this is genius how to teach children multiplication. Use your "hand calculator" to figure 8 and 9 multiplication tables. Where was this when I was in school? (Also, this is a crazy long video for such a simple concept.
Times table trick using your hands: To multiply x by y, where x and y are both integers in the range 6 to 10 inclusive, you work out (x - 5 + y - x 10 + - x) - y). It can be seen that this = + - 100 + 100 - - + xy = xy
Start saving those water bottle lids: Math Facts Race, a great, engaging math activity that can be changed to accommodate lower to higher math learners. AND, you can fit it to engage middle and high school students.